Question

There are 7 girls and 3 boys in a class. Two students are to be

randomly chosen for a special project. What is the probability of
selecting a boy and a girl?

Answer 1

7/15 is the probability of selecting a boy and a girl.

Explanation:

Combination = nCr = n!/((n-r)!r!)

((7C1)(3C1))/(10C2)

= (7*3)/45

=21/45 = 7/15 the probability of selecting a boy and a girl.