MathematicsHard75×since 2002Q4904Three persons P, Q and R independently try to hit a target. I the probabilities of their hitting the target are 34,12{3 \over 4},{1 \over 2}43,21 and 58{5 \over 8}85 respectively, then the probability that the target is hit by P or Q but not by R is :A2164{{21} \over {64}}6421B964{{9} \over {64}}649C1564{{15} \over {64}}6415D3964{{39} \over {64}}6439Check answerSkip