Question

There are 32 students in mrs. worrells classroom. There are 12 boys and 20 girls. She needs to select two students to represent she class for a math contest. She will put all her students names on a piece of paper and randomly select two names, one after the other. What is the possibility that she will select a boy first and then a girl?

A. 1/4
B. 15/64
C. 15/62
D. 1/2

Answer 1

15/62

Explanation:

Answer 2

C. 15/62

Explanation:

The probability of drawing a boy's name first is 12/32. Then the probability of drawing a girl's name is 20/31, assuming the boy's name was not replaced. The joint probabiilty is the product of these:

... (12/32)·(20/31) = (3·4·5·4)/(16·2·31) = 15/62