3 students are selected from a class that has 10 boys and 5 girls. what is the probability that 1 boy and 2 girls are selected?

Chances of drawing a boy the first time = 12/16.

Chances of drawing a boy the second time = 11/15.

Chances of drawing a boy the third time = 10/14.

(12/16) (11/15) (10/14) = about 39.3%.