at the end of a game, each of the five members of a basketball team shake hands with each of the five members of the other team, and all of the players shake hands with the two referees. how many handshakes occur?

If we consider the five members of one team shaking hands with each of the five members of the other team, we can simply count the number of hands the members of one team shake, since this will necessarily count all of the handshakes of the other team. Thus, as each of the five people shakes five hands, this gives  25 handshakes. There are ten basketball players total, and if each shakes hands with two referees, this gives  20 more handshakes. Thus, a total of  45 handshakes occur.