a woman has a problem determining the paternity of her son. her blood type is A, her childs is B. she has three candidates for fatherhood. their...

a woman has a problem determining the paternity of her son. her blood type is A, her childs is B. she has three candidates for fatherhood. their blood types are: man #1 B; man #2, AB; man #3, O. based on blood types the mother says it must have been number 1.