Problem:

Five pirates have to divide 100 gold coins. The rules are: the oldest pirate proposes how to share the coins, and all pirates (including the proposer) vote on it. If 50% or more of the pirates agree, the plan is accepted. If not, the proposer is thrown overboard, and the next oldest makes a new proposal. How does the oldest pirate ensure he survives and gets as many coins as possible?

Scroll to the bottom of the page for the answer

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Solution:

The oldest pirate proposes giving one coin each to the third and fifth pirates and keeps 98 for himself. He knows that without him, the remaining pirates would turn on each other, ensuring the least senior pirates end up with nothing if they don’t agree.