Question

A small class has 10 students, 5 of whom are girls and 5 of whom are boys. The teacher is going to choose two of the students at random. What is the probability that the teacher will choose two boys? Write your answer as a fraction in simplest form.

Answer 1

So,

P(boy) = 5/10 = 1/2

As there are no replacements, after you choose one, you have left 4 boys and 9 people:

P(boy and boy) = 1/2*4/9 = 4/18 = 2/9

Answer: P(boy and boy)=2/9