Skip to content / Đến nội dung
ThichHocToan.com

MathNet 2020 — Math Olympiad Vault — Part 03 Question 42

Math Olympiad Vault · MathNet 2020 — Math Olympiad Vault — Part 03

Question 42

Max repeatedly throws a fair coin in a hurricane. For each throw, there is a $4\%$ chance that the coin gets blown away. He records the number of heads $H$ and the number of tails $T$ before the coin is lost. (If the coin is blown away on a toss, no result is recorded for that toss.) What is the expected value of $|H-T|$?