Question

There are 10 students in a class: 6 boys and 4 girls. If the teacher picks a group of
3 at random, what is the probability that everyone in the group is a girl?

Answer 1

Probability that nbr1 is a girl is p1 = 4/10.

Probability that nbr2 is a girl, given 3 girls left is 3/9

Probability that nbr3 is a girl given 2 girls left is 2/8

$P = (4*3*2)/(10*9*8) = 1/30.$

Answer: 1/30.