Assumption : "Since it is not explicitly given that the bomb hits the target, we have to consider both hit and miss cases." Given answer might be wrong, since probability 0.2 implies that the first plane misses the target every time, i.e. probability of missing target by plane I is 1. Consider 100 bomb drops, out of those 100 drops plane I will hit the target approximately 30 times, so plane II will get the chance to drop the bomb only 70 times out of 100 drops, now once it has get the chance to drop the bomb it will hit the target at a probability of 0.2 i.e. out of 70 times it will probably hit the target 70 x 0.2 = 14 times. So out of 100 bomb drops, plane II will probably hit the target 14 times. So possibly the answer is 0.14.