Question

A, B and C try to hit a target simultaneously but independently. Their respective probabilities of hitting the target are 3/4,1/2,5/8. The probability that the target is hit by A or B but not by C

(a) 21/64

(b) 7/32

(c) 9/64 

(d) 7/8

Answer 1

(a) 21/64

P(A) = 3/4 P(A’) = 1/4 

P(B) = 1/2 P(B’) = 1/2 

P(C) = 5/8 P(C’) = 3/8

Probability of hitting the target = 1