In the ABO blood type system type A and B are codominant and is recessive. If a loving human couple (father's blood type is AO, mother's is BO) decide to express their love as their chosen deity approves and through a mysterious miracle they conceive two children (a year apart, not as twins, thankfully!), what is the probability that the first child is a girl with type o blood and their second child is boy with type AB blood? For full credit you must explain your answer including how you combined probabilities