Question

Mrs. Synder must choose two of her homeroom students to be class representatives. The class consists of 13 girls and 9 boys. Approximately what percent chance is there that the first student chosen is a boy and the second student chosen is a girl? (Round to the nearest percent)

A. 10%

B. 25%

C. 22%

D. 15%

Answer 1

9/22 x 13/21 = 0.25 = 25% B

Answer 2

Answer: B. 25%

Explanation:

Given : Number of boys in the class = 13

Number of girls in the class = 9

Total students = 13+9=22

Now, the number of ways to choose first boy then a girl =
`13*9=117` (1)

Number of ways to choose nay two students :-

`{22}P_(2)=(22!)/((22-2)!)\\\\=(22*21*20!)/(20!)=462` (2)

Now, the probability that the first student chosen is a boy and the second student chosen is a girl :-

`(117)/(462)=0.253246753247\approx0.25` [Divide (1) by (2)]

In percent ,
`0.25*100=25\%`

Hence, approximately 25% chance that the first student chosen is a boy and the second student chosen is a girl.