[X]    Privacy Policy

BrainBashers uses cookies and by using BrainBashers you agree to our use of cookies.

[X]    Common Answers

Have you entered July's Common Answers?

BB Logo Spacer

Puzzle - Answer

Bill and Ben takes turns flipping a coin. Whoever gets the head first is the winner.

If Bill has the first flip, what is the probability that he will win?

 [Ref: ZHIP]

Answer: 2/3.

The probability that he will get a head on his first toss is 1/2, if not, the probability he wins on his second toss is 1/2 + 1/8, etc. The sum of 1/2 + 1/8 + 1/32 + 1/128 = 2/3. QED

Back to the puzzles...



This website uses cookies, for more information please view our privacy policy.