There are 17 men and 26 women in a choir. The choir is going to sing at a concert.
One of the men and one of the women are going to be chosen to make a pair to sing the first song.
(a) Work out the number of different pairs that can be chosen.

(2)
Two of the men are to be chosen to make a pair to sing the second song.
Ben thinks the number of different pairs that can be chosen is 136
Mark thinks the number of different pairs that can be chosen is 272
(b) Who is correct, Ben or Mark?
Give a reason for your answer.

i just need help on b why is it 17x16 and then divide by 2 ? like why divide by 2 why not leave it as 17x16