JAMB Mathematics 1999 Question 42

Question 42

Probability

Three boys play a game of luck in which their respective chances of winning are ½, ⅓ and ¼. What is the probability that one and only one of the boys wins the game?

A.1/24
B.1/12
C.11/24
D.23/24

Show the answer and explanation

Answer: C (11/24)

Explanation

P(exactly one) = ½·⅔·¾ + ½·⅓·¾ + ½·⅔·¼ = 6/24 + 3/24 + 2/24 = 11/24.