Games and stopping · Coin-flip betting · difficulty 3 of 5
How long until it's over
You have $3. You bet $1 at a time on flips of a fair coin: heads you win $1, tails you lose $1. You stop as soon as you have $10 or you go broke. What is the expected number of bets you make?
Answer with an expected value. First lock in a gut guess with an 80% range, then solve it properly, then watch a simulation settle on the truth.
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