In a particular random mating population, the frequency of the O allele of the ABO blood group system is .6, the frequency of A is .3, and the frequency of B is .1.
a) If a type O man and a type A woman produce a child, what is the probability it will be type O?
b) If their first child is type O, what is the probability the second one will also be type O?
c) If the first one is type A, what is the probability the second one will be type O?