Pledge Task - Edison Xiao
Yingsheng "Edison" Xiao
Pledges,
My name is Edison Xiao, and I’m a brother of Scale and Coin. During the pledge process I will give out multiple pledge tasks for signatures from me. Here is the first one:
Brain Teaser (my second favorite):
Note: please refrain from searching online or working with other people. I care more about you taking the effort to solve it rather than getting the correct answer.
There are 1000 bottles with 999 contains water and 1 contains poison. You have 10 mice to find exactly which bottle contains poison. Here are the rules:
· The 1000 bottles are identical and the poison can only be distinguished if the mice which has drunk it die
· One mouse can drink out of multiple bottles and assume there is no limit on the number of bottles each can drink from (e.g. if you want, you can let one mouse drink all 1000 bottles)
· All mice have to drink at the same time and they only have one chance to drink. (i.e. you can’t let one mouse keep drinking until it dies. You also can’t let 5 mice drink first and let the rest 5 drink later based on the result of the first trial)
Question: how do you find the bottle of poison.
Please let me know if you have questions.
Best,
Edison
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Yingsheng “Edison” Xiao
Duke University
BS Economics and BS Computer Science 2014
edison...@gmail.com | 919.699.8696
Yingsheng "Edison" Xiao
Some clarifications:
1. Multiple mice can drink from the same bottle
2. The order of bottles a mouse drinks from doesn’t matter and if they die, they will die at the same time after drinking from all the assigned bottles. Think about it this way: instead of asking the mice to drink from each bottle sequentially, each mouse has its own cup. After selecting which bottles mouse A is to drink from, you pour the drinks into the cup for mouse A and mix the liquid. You do this for all 10 mice and ask them to drink at the same time.
This is not intended to be a consulting type real-life tricky question. It’s more about logic and maybe some math. Please let me know if there are other ambiguities.
Edison
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Yingsheng “Edison” Xiao
Duke University
BS Economics and BS Computer Science 2014