A man alternately tosses a coin and throw a dice, beginning with the coin. The probability that he gets a head in coin before he gets a 5 or 6 in dice, is

Step-by-step solution

A = coin show head B = dice show 5 or 6 P A = 1 2 , P B = 2 6 = 1 3 Hence, the required Probability = P A + P A C P B C P A + P A C P B C 2 P A + … = 1 2 + 1 2 × 2 3 × 1 2 + 1 2 × 2 3 2 × 1 2 + … = 1 2 1 - 1 3 = 1 2 2 3 = 3 4