How can you distribute 3 apple to two mothers and their two daughters given a whole apple to each?

You can distribute the 3 Apples by giving one Apple to each of the two mothers, and then giving the third Apple to one of the daughters. This works because one of the mothers can also be a daughter, meaning there are effectively three individuals: the first mother, the second mother, and one of their daughters. Thus, each person receives one Apple, satisfying the requirement.