Question

Mr minus picks 2 students at random from his class of 31 students.15 of his students are boys. What is the probability he picks 2 girls from the class?

Many thanks.

Answer 1

so there are 15 boys and 16 girls

prob(that both picked are girls)
= C(16,2) / C(31,2) = 120/465 = 8/31

or

prob(girl, girl)
= (16/31)(15/30)
= (16/31)(1/2) = 8/31