2 aeroplanes I and II bomb a target in succession. The probabilities of I and II scoring a hit correctly is 0.3 and 0.2 respectively. The second plane will bomb only if first misses the target. The probability that the target is hit by the 2 nd plane is

Step-by-step solution

Let A be the event that aeroplane-I hit the target correctly and B be the event that aeroplane-II hit the target correctly. array ll & P(A)=0.3 and P(B)=0.2 & P (A^ )=1-P(A)=1-0.3=0.7 array where A^ , first mises the target P (B^ )=1-P(B)=1-0.2=0.8B^ , second misses the target. Let X be the event that target is hit by plane-II aligned =0.7 0.2 & +0.7 0.8 0.7 0.2 & +0.7 0.8 0.7 0.8 0.7 0.2+ aligned =0.14 [1+(0.56)+(0.56)^2+ ]=0.14 [ 1 1-0.56 ] [ 1+0.56+(0.56)^2+ . forms an infinite GP whose sum = a 1-r where a is fi