Please help me with these questions! Lots of points! I already asked Biology and nobody answered me after 2 hours...

A man with type A blood is married to a woman with type O blood. What are ALL of the possible blood types of their children?
A man with type AB blood is married to a woman with type O blood. What are all the possible blood types of their children?
A man with type A blood whose mother was type O is married to a woman with type AB blood. What are the possible blood types of their children and in what proportion?