A hand is a set of five cards chosen from a standard deck of cards (see Exercise 7(b))....

A hand is a set of five cards chosen from a standard deck of cards (see Exercise 7(b)).

Determine the number of hands in which

(a) two cards are in the same suit and one card is in each of the other suits.

(b) two cards are hearts and one card is in each of the other suits.

(c) three cards are hearts and two cards are diamonds.

Reference : Exercise 7 (b)