Question: A man wants to have a party in thirty-one days where he will be serving his 1000 barrels of wine. The only problem is that one of his enemies poisoned one of the barrels. The poison kills any man who drinks any of the wine in about 30 days, give or take a few hours. The man has 10 plants that are also killed by the poison in 30 days and can be used to test the wine. How can identify the single poisoned barrel of wine?
Answer: To do this the man must create 1000 unique groups from the 10 plants in which each group has between 1 and 10 plants, and give each plant wine from a different barrel. He can then throw away the barrel of wine that corresponds to the group that died from the wine.
You have a large number of friends coming over and they all get thirsty. Your first friend asks for 1/2 a cup of water. Your second friend asks for 1/4 a cup of water. Your third friend asks for 1/8 a cup of water, etc.
How many cups of water do you need to serve your friends?
Answer: Just one. If your friends kept asking for water like this forever one cup would be enough.