Logic Riddles - Page 3

-

On October 20 2012 12:42 Gnarly wrote: Show nested quote + On October 19 2012 17:37 nlloser60 wrote: ^^jump out? =) This guy probably youtubed it.

What do you mean I youtubed it.

On October 20 2012 21:52 nlloser60 wrote: Show nested quote + On October 20 2012 12:42 Gnarly wrote:   On October 19 2012 17:37 nlloser60 wrote: ^^jump out? =) This guy probably youtubed it. What do you mean I youtubed it.

*Probably*

Really, it just means that you were right.

"Heard on the Street" is one of the well known brainteaser books used to prepare for these interviews.

On October 18 2012 10:45 Daut wrote: + Show Spoiler + if you shoot at mr gray (1/3) you die immediately, (2/3) you miss, then (2/3)*(2/3) you are HU with gray when he shoots white. this leads to an endless string of 1/3*2/3 type things since you can both miss forever by running bad and it has a formula that i dont remember about cantor sets but we can estimate. your odds of winning are (4/9)*(1/3+2/27+4/243....this seems like it approaches 4/9 would be my guess). (2/3)*(1/3) its HU vs mr white (who kills mr gray after he misses) and (2/3)*(1/3)*(1/3) you WIN (2/3)*(1/3)*(2/3) you die. so your odds of winning are.....(4/9)*(4/9)+ 2/27. so you win 16/81+6/81=22/81 if you shoot at mr white first (2/3) you miss. 2/9 you HU with mr white. (4/27) you win, 8/27 you die. then 4/9 you HU with gray. (16/81) you win, (20/81) you die. (1/3) you hit white. then odds of winning are (1/27+2/243+4/2187....about 1/21?) 16/81+1/21 is smaller than 22/81 shoot at gray first.

If you shoot at white first your odds of winning are 19.857/81 compared to shooting gray at 22/81 thus our best hope for survival lies in the higher percentage because we are calculating the times we win. 27.161% for Gray and 24.514% when shooting white. Am i in the wrong here? Can you elaborate in laymans terms why shooting gray is superior to shooting white because logic tells me we are missing some ev on killing white if we don't go for him as aften as possible. I'd prefer the loop over a certain K.O

we also have to calculate our chances if we miss on purpose

How can it ever be shoot gray first, the only benefit of shooting gray first is you most often get to shoot gray twice to his once but there is no actual value in our first shot so its pointless, miss on purpose.

On October 23 2012 10:57 EvilSky wrote: How can it ever be shoot gray first, the only benefit of shooting gray first is you most often get to shoot gray twice to his once but there is no actual value in our first shot so its pointless, miss on purpose.

true, either miss or shoot white, do the math, tho I'm guessing missing is best

1.) D e f e c a t e

wait im not sure thats right meh i dont have time for this shit -.-;

no wait u have to shoot the guy that is 3/3 because if u hit him and kill him ur not AUTO-dead. u still have 1/3 chance of surviving and then either way they wont be shooting you if miss so u get to go again.

missing is most +Ev tho

Another classic:

A father and a son were in a car. Out of nowhere a truck hit the car. Two ambulances came and the father and son were bought to different hospitals. The doctor was sent in for an operation for the boy and says "I can't operate on this boy this is my son!" How was that possible?

On October 23 2012 21:49 HotChip wrote: Another classic: A father and a son were in a car. Out of nowhere a truck hit the car. Two ambulances came and the father and son were bought to different hospitals. The doctor was sent in for an operation for the boy and says "I can't operate on this boy this is my son!" How was that possible?

It's possible because you did not state that the son and father are related, just simply stated that there is a son and a father.

On October 23 2012 21:49 HotChip wrote: Another classic: A father and a son were in a car. Out of nowhere a truck hit the car. Two ambulances came and the father and son were bought to different hospitals. The doctor was sent in for an operation for the boy and says "I can't operate on this boy this is my son!" How was that possible?

previous answer fits better, but i like this photograph.
+ Show Spoiler +

On October 23 2012 21:49 HotChip wrote: Another classic: A father and a son were in a car. Out of nowhere a truck hit the car. Two ambulances came and the father and son were bought to different hospitals. The doctor was sent in for an operation for the boy and says "I can't operate on this boy this is my son!" How was that possible?

Because they were both on the same car i'm gonna assume they were a grandfather, who is also a father, and a son, whose dad is a doctor.

doctor is his mom duh

On October 24 2012 09:19 player999 wrote: doctor is his mom duh

winner

Or gay father

Oh, I like these! Let me add two of my favourites.

8. Many will have heard this, but we can't miss out on the Monty Hall problem:
You are in a game show, and can choose between 3 closed boxes. One of them contains a car, the other two are empty. You pick box number 1. The show leader then opens box number 2, and it is empty. The show leader then presents you with the option to switch to box number 3. Should you switch?

9. An hour glass with all the sand in the bottom is places on a very accurate scale. The hour glass is turned and the sand start flowing down. Does the scale show more, less or same as before?

I'm a bit curious what the right answer, if there is any, is to the bridge and the three balls. Essentially the options are
a) to reinforce the bridge somehow.
b) loose the weight of the last ball on yourself somehow (clothes, etc)
c) transport the ball across in a way so that it doesn't put it's weight on the bridge at the same time you do, or not at all. Like pulling with a rope after you, rolling across first, throwing, raft, etc.

And neither of those really sound like an answer that I'd expect from riddle like these. Either I missed something, or this is an "impossible" question to just test the inventiveness of people.

On October 22 2012 18:50 player999 wrote: we also have to calculate our chances if we miss on purpose

Gray will obv aim for white. If he hits, it will be showdown between you and gray guy, and you go first. Call this scenario A. If he missed, you will have one chance to take down white, then you die. This is scenario B.

You can win in scenario A on shot 1 (ie, gray hits white, you hit gray), on shot 2 (gray hits white, you miss gray, gray miss you, you hit gray), 3, etc. Let's call these scenario A1, A2, A3 etc. The probabilities for these are

A1: 2/3 * 1/3
A2: 2/3 * (2/3 * 1/3) * 1/3
A3: 2/3 * (2/3 * 1/3) * (2/3 * 1/3) *1/3
...

Ie, each extra iteration gives an extra factor 2/3*1/3 = 2/9. The sum of all these are

2/3 * Sum_{i from 0 to infinity} (2/9^i) * 1/3.

The geometric series Sum_i (x^i) is 1/(1-x), so the probability to win through scenario A is 2/3 * 1/(1-2/9) * 1/3 = 2/9 * 9/(9-2) = 2/7.

The probability win through scenario B is simply 1/3*1/3 = 1/9 as gray have to miss, and you have to hit.

So total chance to win if we miss on purpose is 2/7 + 1/9 = 18/63 + 7/63 = 25/63 which is just below 40%. Not too bad imo, considering how bad of a shot mr black is.