Two aeroplanes I and II bomb a target in succession. The probabilities of I and II scoring a hit correctly are 0.3 and 0.2, respectively. The second plane will bomb only if the first misses the target. The probability that the target is hit by the second plane is (A) `0.06`                                                     (B) `0.14` (C) `7/22`                                                       (D) `0.7`

Explanation

P(A) = Target not hit by plane I
`P(E_1)` = Target hit by plane II
`P(E_2)` = Target not hit by plane II
`P(E_1|A)=(P(A)P(E_1|A))/(P(A)P(E_1|A)+P(A)P(E_2|A))`
`=((0.7)(0.2))/((0.7)(0.2)+(0.7)(0.8))=0.2`