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ITT some basic quant interview questions
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Date: February 4th, 2013 4:57 PM Author: awkward ticket booth main people sample questions for intro level business analyst type job (not quant but you have to have an intuitive grasp of numbers)
starting with the easiest:
there's a pond with lily pads on it. every day, the number of lily pads doubles. on the 40th day, the pond is completely covered. on which day is the pond half covered? |
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Date: February 4th, 2013 4:58 PM Author: Cordovan locale 39 (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568152) |
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Date: February 4th, 2013 4:58 PM Author: wine multi-billionaire gaming laptop i dunno, 20? (blank stare) (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568160) |
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Date: February 4th, 2013 4:58 PM Author: curious know-it-all mental disorder idea he suggested serious q: has ANYONE not heard this question before? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568161) |
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Date: February 4th, 2013 4:59 PM Author: Cordovan locale i never had but it's incredibly easy for a smart person (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568166) |
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Date: February 4th, 2013 5:00 PM Author: Mind-boggling apoplectic toaster tcr. It doubles every day. It is covered on day 40. what day is it half covered. Gee. The day before. Duh. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568181) |
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Date: February 4th, 2013 5:01 PM Author: awkward ticket booth main people it's question one, little pumo breh. relax (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568186) |
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Date: February 4th, 2013 5:02 PM Author: Cordovan locale i could see how someone dumb could be confused by it (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568192) |
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Date: February 4th, 2013 5:03 PM Author: curious know-it-all mental disorder idea he suggested fwiw, I read it in a book of brain teasers when I was like 5 years old, and I was too dumb to get it at that age. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568199) |
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Date: February 4th, 2013 5:49 PM Author: obsidian national security agency office 2^n-1= 20/2 or something basic (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568525) |
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Date: February 4th, 2013 5:56 PM Author: Scarlet quadroon wtf are you even answering when the correct answer was the first response (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568556) |
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Date: February 4th, 2013 9:40 PM Author: Lavender Fanboi (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22569828) |
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Date: February 5th, 2013 8:34 PM Author: obsidian national security agency office (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22576477) |
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Date: February 8th, 2013 10:18 PM Author: passionate public bath could be 38 too if question doesn't specify that the 40th day results in "just-barely" coverage.
if some of those pads are pushing over the banks onto the shore because it's crowded, then it likely became 1/2 full some time during day 38. |
Date: February 4th, 2013 4:58 PM Author: awkward ticket booth main people #2. a bat and a ball cost $1.10. the bat costs $1 more than the ball. how much do they each cost (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568163) |
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Date: February 4th, 2013 4:59 PM Author: Cordovan locale 105
5 |
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Date: February 4th, 2013 5:00 PM Author: Soul-stirring Sooty Gay Wizard jfc (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568182) |
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Date: February 4th, 2013 5:11 PM Author: Khaki cocky sanctuary this seemed easy to me (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568258) |
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Date: February 4th, 2013 5:02 PM Author: adventurous red nibblets people who are hurt 1
10 |
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Date: February 4th, 2013 4:59 PM Author: house-broken field It takes a man 1 hour to dig a hole. How long does it take him to dig half a hole? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568174) |
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Date: February 4th, 2013 5:31 PM Author: useless slippery church building Is he gay or straight? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568409) |
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Date: February 4th, 2013 5:32 PM Author: house-broken field straight and, indeed, cisgendered (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568414) |
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Date: February 4th, 2013 5:33 PM Author: Scarlet quadroon there's no such thing as "half a hole" it's either a hole or its not (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568422) |
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Date: February 4th, 2013 11:11 PM Author: house-broken field you're hired (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22570510) |
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Date: February 4th, 2013 6:50 PM Author: Swashbuckling sable hospital what does the half hole look like? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568880) |
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Date: February 4th, 2013 5:00 PM Author: awkward ticket booth main people #3
what is the sum of all numbers from 1-99? no calculator/outside aids allowed. also describe how you would do the calculation |
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Date: February 4th, 2013 5:00 PM Author: Cordovan locale 4900 (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568184) |
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Date: February 4th, 2013 5:02 PM Author: curious know-it-all mental disorder idea he suggested 4950 (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568193) |
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Date: February 4th, 2013 5:03 PM Author: Cordovan locale yep, i missed that one (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568202) |
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Date: February 4th, 2013 5:01 PM Author: adventurous red nibblets people who are hurt 12 (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568190) |
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Date: February 4th, 2013 5:03 PM Author: Mind-boggling apoplectic toaster 1 + 99 = 100.
2 + 98 = 100.
and so on. so we end up with 49 pairs with a value of 100 each. 49 x 100 = 4900. We have 1 50 left over. 4950. |
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Date: February 4th, 2013 5:04 PM Author: nighttime temple oh, what a gauss (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568208) |
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Date: February 4th, 2013 5:06 PM Author: Soul-stirring Sooty Gay Wizard (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568224) |
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Date: February 4th, 2013 5:19 PM Author: confused affirmative action new version lol (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568312) |
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Date: February 4th, 2013 5:24 PM Author: dark cuckoldry stead (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568345) |
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Date: February 4th, 2013 5:31 PM Author: Fishy vigorous shrine blank bumping this to sound smart because the name gauss is math-related. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568404) |
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Date: February 4th, 2013 5:33 PM Author: dark cuckoldry stead no, it's a reference to a story about gauss in kindergarten (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568418) |
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Date: February 5th, 2013 7:01 PM Author: provocative lodge juggernaut (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22575750) |
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Date: February 4th, 2013 5:07 PM Author: Citrine place of business 4950.
to find the sum of consecutive intgers, the formula is simple (i believe it was discovered by gauss). add the first and last integers in the sequence and then multiply that by half of the total numbers in the sequence. so here, it's 1+99=100. and then 100*49.5=4950 |
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Date: February 4th, 2013 5:13 PM Author: Khaki cocky sanctuary oh this is more elegant than mine, I just figured that there are pairs of numbers that will each equal to 100, starting with 1+99, 2+98, etc., but there will only be 49 of them because 50 does not appear twice. So 49x100, and then add the 50. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568273) |
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Date: February 5th, 2013 6:52 PM Author: 180 indian lodge generalized bond i believe it was before gauss was president. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22575647) |
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Date: February 4th, 2013 5:12 PM Author: Khaki cocky sanctuary 4950? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568265) |
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Date: February 4th, 2013 5:26 PM Author: dark cuckoldry stead 594
I sample the sum of the first eleven numbers in the series: 1+2+3+4+5+6+7+8+9+10+11 = 66.
From this sample, I can reasonably estimate that each sample of eleven numbers in the overall series sums up to 66, and the total number of samples of eleven numbers is 99/11 = 9. therefore the total sum for 9 samples would be 66*9 = 594 +/- 7.4 at 95% confidence |
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Date: February 4th, 2013 5:30 PM Author: Khaki cocky sanctuary lol ty (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568401) |
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Date: February 4th, 2013 5:57 PM Author: salmon principal's office half-breed You might laugh but many "genuisrs" think exactly this way (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568558) |
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Date: February 5th, 2013 7:00 PM Author: low-t vivacious meetinghouse And that is precisely why enormous quant funds go bust. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22575746) |
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Date: February 5th, 2013 7:02 PM Author: low-t vivacious meetinghouse *uses 100 to 1 leverage -- is ok with 95% confidence intervals* (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22575769) |
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Date: February 5th, 2013 7:05 PM Author: curious know-it-all mental disorder idea he suggested (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22575813) |
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Date: February 8th, 2013 10:24 PM Author: appetizing friendly grandma antidepressant drug scholarship (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22599096) |
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Date: February 5th, 2013 7:48 PM Author: violet double fault coffee pot Imagine a 99 x 99 stack of unit area blocks. Then divide the stack in half by a diagonal line going top left to bottom right.
The question is equivalent to asking what is the total area of the blocks either entirely to the left of the line or cut by the line.
(99 x 99)/2 gives you the area to the left of the line but then you have to account for an extra 99 half-blocks for those blocks cut by the line, so:
(99 x 99)/2 + (99 x 0.5) = 4950 |
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Date: February 4th, 2013 5:05 PM Author: nighttime temple A, B, C and D represent digits from 0-9. ABC + CBA = ABCD. Solve, show work. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568215) |
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Date: February 4th, 2013 5:11 PM Author: Cordovan locale no clue (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568260) |
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Date: February 4th, 2013 5:12 PM Author: nighttime temple actually, never mind, it should be ABC + CBA = BBCB... i mixed up two problems when trying to remember them (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568263) |
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Date: February 4th, 2013 5:16 PM Author: Khaki cocky sanctuary EDIT, wait I almost have it (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568291) |
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Date: February 4th, 2013 5:19 PM Author: nighttime temple no, this one has at least one solution
edit:
oh, i see why this is confusing everyone. ABC is a 3 digit number, not A*B*C |
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Date: February 4th, 2013 5:20 PM Author: Khaki cocky sanctuary A = 9, B = 1, C = 2? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568317) |
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Date: February 4th, 2013 5:20 PM Author: nighttime temple almost, but this misses a carry... 219+912 = 1131 (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568324) |
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Date: February 4th, 2013 5:21 PM Author: Khaki cocky sanctuary oh good point. dood below has it. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568331) |
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Date: February 4th, 2013 5:18 PM Author: curious know-it-all mental disorder idea he suggested was just about to ask if it was impossible, jfc (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568306) |
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Date: February 4th, 2013 5:48 PM Author: Scarlet quadroon You first notice that B must equal 1 since it's the only number that can be carried to the thousands place when adding merely two numbers together. From there it flows fairly easily. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568517) |
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Date: February 4th, 2013 5:18 PM Author: awkward ticket booth main people 2A = B^2? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568307) |
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Date: February 4th, 2013 5:19 PM Author: Opaque point skinny woman ABC=813 CBA=318 BBCB=1131
pretty simple once you realize that B has to be 1. if you are adding 2 3-digit numbers, the largest possible sum is 1998 (999+999). so B must be 1. C+A must equal 1, so the possible combinations are like 7, 4 or 8, 3, etc. i plugged in 8, 3 first and got the right answer. |
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Date: February 4th, 2013 5:20 PM Author: nighttime temple correct on the key trick with the B and right overall (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568320) |
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Date: February 4th, 2013 5:27 PM Author: Khaki cocky sanctuary yeah I caught the B=1 thing but then I made a sloppy error above (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568376) |
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Date: February 4th, 2013 8:40 PM Author: Wild Concupiscible Church You mean C+A must equal 11. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22569372) |
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Date: February 8th, 2013 10:35 PM Author: contagious plaza jew 8 1 3 (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22599206) |
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Date: February 4th, 2013 6:04 PM Author: Beady-eyed Wagecucks nasty question because of the way it uses "digits" combined with the notation. if it were a free response test i'd be pwned hard thinking ABC was A times B times C. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568594) |
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Date: February 4th, 2013 5:15 PM Author: awkward ticket booth main people #4
how would you obtain the sum of all results of a set of 1-10 multiplication tables? |
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Date: February 4th, 2013 5:16 PM Author: Khaki cocky sanctuary Not sure I understand, a sum of all the products? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568293) |
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Date: February 4th, 2013 5:17 PM Author: awkward ticket booth main people yeah, products (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568299) |
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Date: February 4th, 2013 5:17 PM Author: nighttime temple sum of the first row is 5*11 (using the gauss formula above)
each row is n*(first row) where n is the value of the row digit
so 55 + 2*55 + ... + 10*55
iow, (1+2+...+10)*55 = 55^2 |
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Date: February 4th, 2013 6:10 PM Author: lascivious gunner newt fark, i am dumb (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568633) |
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Date: February 4th, 2013 5:50 PM Author: Scarlet quadroon sum(sum(ij),i=1..10),j=1..10) sum(j*sum(i,i=1..10),j=1..10) sum(j*55,j=1..10) 55*sum(j,j=1..10) 55*55 3025 |
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Date: February 4th, 2013 5:20 PM Author: confused affirmative action new version (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568318) |
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Date: February 4th, 2013 5:21 PM Author: Khaki cocky sanctuary Wait, these are questions for quant doods? I thought those guys had to be able to do, like, actual math. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568329) |
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Date: February 4th, 2013 5:22 PM Author: curious know-it-all mental disorder idea he suggested OP said:
>sample questions for intro level business analyst type job (not quant but you have to have an intuitive grasp of numbers) |
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Date: February 4th, 2013 5:22 PM Author: awkward ticket booth main people u fail reading comp breh. this will get you a 60-80k BI analyst type job, 2-3 years out of college-ish. plus these are the easiest ones i could remember, they get progressively harder (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568336) |
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Date: February 4th, 2013 5:23 PM Author: curious know-it-all mental disorder idea he suggested poast the hard ones, there are some smart doods ITT (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568342) |
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Date: February 4th, 2013 5:31 PM Author: lascivious gunner newt really? i didn't think brain teasers were used for these jobs (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568405) |
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Date: February 4th, 2013 5:22 PM Author: adventurous red nibblets people who are hurt how many punctuation marks constitutes a full pumo? show your work. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568332) |
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Date: February 4th, 2013 5:26 PM Author: nighttime temple btw if you doods like these problems you should register an alcumus account (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568358) |
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Date: February 4th, 2013 5:28 PM Author: awkward ticket booth main people You are offered to play a game of chance. A fair coin is tossed repeatedly until you get the first tails, at which point the game ends and you get the prize. The prize "pot" starts at $1 and doubles each time you get heads. So for instance, if you get heads the first toss, the pot becomes $2. If you get heads again the second toss, the pot becomes $4. If you get heads the third time, the pot becomes $8. If the fourth toss gives you the tail of the coin, you win and take home the $8 prize.
Before you play, you must pay a fee to enter this game. The question is, what's the maximum amount you're willing to pay in order to play this game? |
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Date: February 4th, 2013 5:31 PM Author: Indecent rambunctious casino weed whacker $1.75 (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568406) |
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Date: February 4th, 2013 5:32 PM Author: Aqua Persian Box Office why? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568416) |
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Date: February 4th, 2013 5:32 PM Author: Aqua Persian Box Office $1 (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568417) |
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Date: February 4th, 2013 5:34 PM Author: confused affirmative action new version i think your ev is better but i cant do the math but every time you don't hit tails or whatever, you turn more than $1. so the number has to be > 1 (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568427) |
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Date: February 4th, 2013 5:33 PM Author: confused affirmative action new version $3.33 idk (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568419) |
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Date: February 4th, 2013 5:35 PM Author: Opaque point skinny woman i'm getting $2.53 (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568435) |
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Date: February 4th, 2013 5:36 PM Author: awkward ticket booth main people ANSWER:
http://en.wikipedia.org/wiki/St._Petersburg_paradox |
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Date: February 4th, 2013 5:30 PM Author: Fishy vigorous shrine Got this one during my b-school interview:
You have a lamp that you need to set on a timer. You want it to come on for two periods daily: 5-8am and 5-8pm. You have an unlimited number of light timers that each can allow power to the lamp for one period (think: those cheap Ikea timers that would allow the light to be on for one period per day). You can run these timers in sequence.
How many of these timers would the lamp require, and each set to what period, so that it will be on for these two time periods during the day?
edit: 24 hour timers. Lamp has one cord going to a single outlet. Multiple timers would run in sequence.
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Date: February 4th, 2013 5:32 PM Author: confused affirmative action new version wat? one timer set 5-8. wat
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Date: February 4th, 2013 5:33 PM Author: Fishy vigorous shrine one timer set from 5-8am would only have the light come on for that one period. the light would stay off from 5-8pm. so, no. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568423) |
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Date: February 4th, 2013 5:35 PM Author: confused affirmative action new version oh, it only goes one 24 hour period? two timers, one from 5-8 another from 5-8? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568437) |
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Date: February 4th, 2013 5:36 PM Author: Fishy vigorous shrine the timers are in sequence. so two timers, one set for 5-8am and the other from 5-8pm would not allow either to work.
Editing the OP. |
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Date: February 4th, 2013 5:37 PM Author: Khaki cocky sanctuary there is no way for the sequence to work at all then, assuming they are daisy-chained (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568456) |
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Date: February 4th, 2013 5:38 PM Author: confused affirmative action new version i dont understand what the timers do man, sorry
it's either 2 or 3 with the stuff you've specified but i dont understand the rules w/r/t timers. |
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Date: February 4th, 2013 5:35 PM Author: Khaki cocky sanctuary so it's a 24 hour timer? But wouldn't the timer directly plugged into the outlet prevent power from getting to any subsequent timers in the chain for anything other than the programmed time? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568438) |
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Date: February 4th, 2013 5:38 PM Author: Fishy vigorous shrine Well, you could set a timer to be on from, say, 1am to midnight. And then set the second timer in sequence so no power gets to the lamp except from, say, 1-3pm. Then despite two timers, the lamp would only be on from 1-3pm. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568465) |
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Date: February 4th, 2013 5:41 PM Author: Khaki cocky sanctuary but could you do this with two different times? at some point isn't one of the timers in the chain going to have to be set to a single short time period? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568482) |
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Date: February 4th, 2013 5:50 PM Author: Khaki cocky sanctuary something has to be wrong about this hypo (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568527) |
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Date: February 4th, 2013 6:23 PM Author: Exciting Milky Cruise Ship you god damn retards 2 timers 5am to 8pm 5pm to 8am |
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Date: February 5th, 2013 6:15 PM Author: curious know-it-all mental disorder idea he suggested I got this in like a second once I understood the question, but it was explained so poorly I had to read most of the subthread to figure out how the goddamn timers were supposed to work (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22575391) |
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Date: February 5th, 2013 6:19 PM Author: Offensive grizzly tanning salon scourge upon the earth B-Schools (well top ones) don't normally have quant questions. Where was this? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22575422) |
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Date: February 4th, 2013 5:35 PM Author: awkward ticket booth main people this is a well known one
One hundred ants are dropped on a meter stick. Each ant is traveling either to the left or the right with constant speed 1 meter per minute. When two ants meet, they bounce off each other and reverse direction. When an ant reaches an end of the stick, it falls off.
At some point all the ants will have fallen off. The time at which this happens will depend on the initial configuration of the ants.
Question: over ALL possible initial configurations, what is the longest amount of time that you would need to wait to guarantee that the stick has no more ants? |
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Date: February 4th, 2013 5:36 PM Author: Khaki cocky sanctuary One minute. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568447) |
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Date: February 4th, 2013 5:39 PM Author: confused affirmative action new version YES I WIN WHERE'S MY 80K (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568470) |
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Date: February 4th, 2013 5:41 PM Author: Khaki cocky sanctuary this one seems really easy. Drop them all at opposite ends of the stick, 30s in, 30 s out. Done. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568487) |
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Date: February 4th, 2013 5:56 PM Author: Scarlet quadroon tbf the Q is "what is the maximum time possible" not "please find the length of time of one configuration you think is the maximum" your solution is not rigorous |
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Date: February 4th, 2013 6:03 PM Author: Khaki cocky sanctuary Can we choose which direction each ant starts traveling? I suppose the longest version in that case would be a configuration with each ant 1/100 of a meter apart, but that seems like a giant pain in the ass to calculate. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568581) |
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Date: February 5th, 2013 7:44 PM Author: vibrant chartreuse locus incel Except that when the first ants hit each other, they're going to turn around and then hit the ants behind them and turn back around. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22576128) |
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Date: February 5th, 2013 7:46 PM Author: awkward ticket booth main people the key to solving this problem is to understand that 2 ants hitting each other and turning around is the same thing as 2 ants passing right through each other. so all the bouncing back and forth is just a red herring - the maximmum time it takes for all ants the clear the stick is the same as the maximum time it would take one ant to clear the stick - 1 minute (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22576141) |
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Date: February 4th, 2013 5:37 PM Author: confused affirmative action new version idk 60s? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568452) |
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Date: February 4th, 2013 5:39 PM Author: Pearly bisexual indirect expression kitty cat 1 minute (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568468) |
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Date: February 4th, 2013 5:36 PM Author: lascivious gunner newt i am dumb (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568444) |
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Date: February 4th, 2013 5:46 PM Author: awkward ticket booth main people A shopkeeper says she has two new baby beagles to show you, but she doesn't know whether they're male, female, or a pair. You tell her that you want only a male, and she telephones the fellow who's giving them a bath. "Is at least one a male?" she asks him. "Yes!" she informs you with a smile.
What is the probability that both beagles are male? |
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Date: February 4th, 2013 5:48 PM Author: Khaki cocky sanctuary 1/3, although something has always struck me as wrong with the reasoning behind this (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568518) |
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Date: February 4th, 2013 5:53 PM Author: nighttime temple cases where one is a male:
MF, FM, MM
in 1/3, both are male |
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Date: February 4th, 2013 5:58 PM Author: Khaki cocky sanctuary This is the way it was explained to me, but I find this suspect. You are treating it as though there are "positions" for the dogs. But as I see it, there is only one dog and the other dog, so there should really only be two cases
MF MM
where the second spot represents "the other dog."
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Date: February 4th, 2013 6:02 PM Author: Arousing maroon corner This would be the case if you were to say "the first puppy is Male, what are the odds both are male?" (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568577) |
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Date: February 4th, 2013 6:17 PM Author: Khaki cocky sanctuary but why is there a "first" and "second" puppy at all? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568695) |
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Date: February 4th, 2013 6:28 PM Author: Arousing maroon corner There isn't the way it is worded, but there is the way you are interpreting the odds. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568765) |
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Date: February 4th, 2013 6:03 PM Author: nighttime temple the dogs don't have positions, but they are distinct individuals. "is at least one male" is fulfilled by either one being male or by both being male.
your reasoning is correct for the question "is dog A male" but not for the question "is at least one of dog A or dog B male" |
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Date: February 4th, 2013 6:24 PM Author: Khaki cocky sanctuary I understand that, but I disagree with the premise of assigning them "A" and "B"
Let's phrase the question another way -- you are going to a wedding, and at least one of the people getting married is male. Assuming homos and heteros are equally distributed, what is the probability of the couple being gay? The answer is 50%. There's no left and right, A and B, 1 and 2 slot, etc., you just have a man, and he is either marrying a man or a woman. 50%. |
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Date: February 4th, 2013 6:34 PM Author: Arousing maroon corner No you have 4 scenarios: Mgroom Mbride Mgroom Fbride Fgroom Fbride Fgroom Mbride (lol)
You've eliminated the FF wedding, but you have a 1/3 shot at dat MM
edit: If you know in advance that it is 1 man marrying either a man or a woman, then you are right. But if you are going in blind and ask someone "is atleast 1 partner a man", then the odds play out as I showed above. |
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Date: February 4th, 2013 6:00 PM Author: Arousing maroon corner You have Puppy A and Puppy B. Four equally likely outcomes:
Aboy Bgirl Aboy Bboy Agirl Bgirl Agirl Bboy
The phone call eliminates one outcome (Agirl, Bgirl)
Of the remaining possible outcomes, 1/3 is Boy-Boy |
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Date: February 4th, 2013 6:21 PM Author: Khaki cocky sanctuary I get that, but I think the premise of assigning "A" and "B" slots is wrong. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568717) |
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Date: February 4th, 2013 6:27 PM Author: Arousing maroon corner With the wording of the problem, you assume that the person on the phone knows the sex of both puppies.
It's similar to the monty hall problem, where the fact that the host knows that he is showing you a losing door changes the odds vs if he were to show you a door at random and it happens to be a loser.
If he had only looked at one dog, and it happened to be a male, your numbers are correct. |
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Date: February 4th, 2013 7:35 PM Author: curious know-it-all mental disorder idea he suggested the point is, each puppy has a 50/50 chance of being male or female. if you want to keep track of each puppy separately (which you need to to do the math correctly), you need to label them somehow. whether it's "A" and "B" or "X" and "Y" or "dicks" and "dongs" doesn't matter, but you need to keep track of both puppies separately. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22569111) |
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Date: February 4th, 2013 5:51 PM Author: Pearly bisexual indirect expression kitty cat 50% (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568533) |
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Date: February 4th, 2013 6:16 PM Author: lascivious gunner newt this is a classic, but a bit of a gay question (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568685) |
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Date: February 4th, 2013 7:10 PM Author: Khaki cocky sanctuary Here's another way to think about it:
The guy on the phone is effectively saying "I have two puppies here, one to my right and one to my left, and at least one of them (the one I'm looking at) is male"
There are four possibilities now:
1) The one he is looking at, R, is male, and L is also male 2) The one he is looking at, L, is male, and R is also male 3) The one he is looking at, R, is male, and L is female 4) The one he is looking at, L, is male, and R is female
The odds of two males becomes 50%. I don't see why this is any more or less a reasonable way to interpret the problem than the standard answer. |
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Date: February 5th, 2013 6:53 PM Author: Odious jap roommate Your logic makes no sense (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22575654) |
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Date: February 4th, 2013 5:50 PM Author: awkward ticket booth main people You are on a rowboat in the middle of a large, perfectly circular lake. On the perimeter of the lake is a monster who wants to eat you, but fortunately, he can't swim. He can run (along the perimeter) exactly 4x as fast as you can row, and he will always run towards the closest bit of shore to your boat. If two paths take him to this location equally quickly, he will arbitrarily choose one. If you can touch shore even for a second without the monster already being upon you, you can escape. The monster can reverse direction instantaneously and you can turn your boat instantaneously. Suggest a strategy that will allow you to escape, and prove that it works (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568529) |
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Date: February 4th, 2013 5:55 PM Author: Khaki cocky sanctuary This is simple -- just row in a straight line to the furthest point from the monster (the point directly opposite the monster) when you start rowing. You will get there faster than him. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568551) |
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Date: February 4th, 2013 5:59 PM Author: Pearly bisexual indirect expression kitty cat no this won't work. you'd travel a distance of R and the monster would have to go pi*R but he travels 4 times as fast as you and 4>pi (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568564) |
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Date: February 4th, 2013 6:01 PM Author: awkward ticket booth main people he only has to cover 3.14*r so he will catch you (because he only needs to cover half the perimeter if you start from teh opposite point of him) (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568571) |
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Date: February 4th, 2013 6:04 PM Author: Khaki cocky sanctuary oh yeah I fucked that up. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568593) |
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Date: February 4th, 2013 6:13 PM Author: nighttime temple the answer involves arc-shaped paths... i'm still trying to make the math work, but that's the only way you can stay ahead of the monster (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568655) |
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Date: February 4th, 2013 6:40 PM Author: nighttime temple ok, i think i've got it.
my original idea was to paddle in a circle with a radius of r/2 (a circle inscribed so that r of the pond is its diameter). this had the virtue of forcing the monster to run towards a spot that you were moving away from. sadly, he only has to cover 3/2 pi r in the time you take to travel 1/2 pi r, so you still lose b/c of his speed advantage. (he only needs to be 3x as fast as you to arrive at the same moment).
this made me realize that the monster's speed advantage always allows him to catch you on an arced course whenever the distance you travel is that of a circle with arc >= 1/4r
so i think you win by 1) paddling in a circle with arc < r/4, which should allow you to get to a point where he is trailing the point your bow is pointing at, and then 2) go straight to the shore
do i get to be a janitor for quants with this answer |
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Date: February 5th, 2013 7:48 PM Author: awkward ticket booth main people this is correct if you're saying what i think you're saying which is that you can spiral out until you reach a circle of radius 1/4r (at which point you can no longer outdistance him). then take off like a bandit to the opposite side of the shore from where he is (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22576157) |
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Date: February 5th, 2013 11:55 PM Author: diverse bawdyhouse immigrant This is my favorite. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22578107) |
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Date: February 4th, 2013 5:54 PM Author: awkward ticket booth main people Yragle the pirate has 100 white pearls and 100 black pearls. The white pearls are worthless, the black pearls are priceless. He will let you distribute the pearls between two sacks, labeled "Heads" and "Tails." After you distribute the pearls, you flip a fair coin and choose a pearl at random from the corresponding sack. How should you distribute the pearls between the two sacks to maximize your odds of getting a black pearl? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568545) |
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Date: February 4th, 2013 5:57 PM Author: Pearly bisexual indirect expression kitty cat edit: i'm dumb (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568559) |
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Date: February 4th, 2013 6:09 PM Author: Arousing maroon corner 1 black pearl in one bag 99 black pearls and 100 white pearls in the other
edit: I mean, assuming you have to place every pearl in a bag. Otherwise, just dump those TTT white pearls. |
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Date: February 4th, 2013 6:44 PM Author: lascivious gunner newt going to go walk in front of a bus now, thanks (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568855) |
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Date: February 4th, 2013 6:11 PM Author: vengeful set hairy legs what is the mass of the earth? (i got this one in an interview once) (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568644) |
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Date: February 4th, 2013 6:29 PM Author: Khaki cocky sanctuary if you said "weight" I would say trick question, but mass I think is actually calculable (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568769) |
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Date: February 4th, 2013 6:48 PM Author: vengeful set hairy legs it is. i fumbled around for 25 minutes but got kind of close (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568870) |
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Date: February 5th, 2013 8:37 PM Author: insane mad-dog skullcap location What's the calculation? I remember the # from an earth science class but no cloo how I'd answer if it wasn't drilled into my memory. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22576500) |
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Date: February 5th, 2013 10:00 PM Author: vengeful set hairy legs 4/3*pi*r^3 for volume of sphere then i multiplied it by some made up density number (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22577214) |
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Date: February 5th, 2013 11:46 PM Author: insane mad-dog skullcap location lol wtf earth isn't a sphere (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22578004) |
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Date: February 4th, 2013 6:45 PM Author: confused affirmative action new version the mass of love x dedication so 0 (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22568860) |
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Date: February 5th, 2013 6:58 PM Author: 180 indian lodge generalized bond most of these are all pseudo-intellectual gay ass questions.
only the ones that required inventing a formula are worth looking at. |
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Date: February 5th, 2013 7:01 PM Author: Odious jap roommate You go on a game show where there are two boxes : H and T. you flip a coin and if its heads you are handed box H, tails you are handed box T. the host then tells you that one of the boxes contains twice as much money as the other and then gives you the option to switch, but does not tell you the total amount in the boxes, what do you do? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22575749) |
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Date: February 5th, 2013 7:08 PM Author: low-t vivacious meetinghouse put on my robe and wizard hat (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22575837) |
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Date: February 8th, 2013 10:09 PM Author: Odious jap roommate (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22598969) |
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Date: February 5th, 2013 7:20 PM Author: Excitant henna digit ratio alpha switch. 50% chance of doubling your money is worth more than a 50% chance of halving it. mathematically, .5(2x+.5x) = .5(2.5*x)>x. (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22575936) |
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Date: February 5th, 2013 7:22 PM Author: Odious jap roommate Now that you've switched the host gives you the option to switch back to the original box, what do you do? (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22575956) |
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Date: February 5th, 2013 10:12 PM Author: curious know-it-all mental disorder idea he suggested lol, pwn (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22577290) |
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Date: February 5th, 2013 8:34 PM Author: Odious jap roommate (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22576478) |
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Date: February 5th, 2013 9:58 PM Author: irate emerald goal in life http://en.wikipedia.org/wiki/Two_envelopes_problem (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22577196) |
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Date: February 5th, 2013 7:07 PM Author: low-t vivacious meetinghouse *wins nobel prize*
http://en.wikipedia.org/wiki/Long_Term_Capital_Management
*destroys fund, almost collapses global economy* |
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Date: February 5th, 2013 7:33 PM Author: Cobalt supple school cafeteria I got this one:
"Think out loud and let us listen to how you estimate the cans of paint it will take to paint the Verrazano Narrows Bridge." |
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Date: February 5th, 2013 7:43 PM Author: French bearded step-uncle's house faggot firefighter the correct answer to all of these is "oh I'm sorry. I didn't realize it was 1997." (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22576115) |
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Date: February 5th, 2013 8:18 PM Author: Odious jap roommate (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22576387) |
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Date: February 8th, 2013 10:15 PM Author: passionate public bath (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#22599015) |
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Date: July 25th, 2017 11:59 AM Author: awkward ticket booth main people (http://www.autoadmit.com/thread.php?thread_id=2175711&forum_id=2#33850985) |