## March 4, 2015

### Poisoned Wine Puzzle

You have 240 barrels of wine, one of which has been poisoned. After drinking the poisoned wine, one dies within 24 hours. You have 5 slaves whom you are willing to sacrifice in order to determine which barrel contains the poisoned wine.
How do you achieve this in 48 hours?

Anonymous said...

In the first round, 32 barrels will be untouched.
Only one drinks from 16 distinct barrels. Hence 16x5=80 barrels are tasted by 1.
Two distinct slaves drink 8 barrels, hence another 8x10=80 barrels are tasted by 2.
Three drink 4 barrels, and hence 40 are tasted by 3.
Four drink 2, and hence 2x5=10 are tasted by 4.
All five drink 1.
The maximum number 243 barrels with one poisoned barrel could be covered with this method.
If everyone dies, then the only barrel everyone drank from is poisoned.
If four die, then in the second round the survived one drinks one of the two the four drank. And the answer will follow.
If 3 die, then in the second round, among the four barrels 3 drank, one barrel is not touched, two survived drink taste one distinct barrel, each one survived one drink from 1 distinct barrel. And the answer follows.
For the rest a similar but a bit more complicated arguments applies.

Anonymous said...

Impossible they'll all get drunk