Allen and Blake are practicing archery. The probability that
Allen hits a given target is ?, while the probability that
Blake hits a given target is ?. Assume these probabilities are
independent. Allen and Blake aim at a single target and fire at the
same time. a) If the target was hit, what is the probability that
it was hit by both Allen and Blake? b) If the target was hit, what
is the probability that it was hit by Blake?