395.The Hundredth Coin
★★★conditional probabilityCh. 2 — Axiomatic and Conditional Probability444+ Problems in Probability
A pile has 100 coins: 99 fair and 1 double-headed. You pick a coin at random and flip it 10 times, observing 10 heads. What is the probability you picked the double-headed coin?
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Odds form: prior , and each head doubles the odds.
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