Question

In a certain class of​ students, there are 11 boys from​ Wilmette, 7 girls from​ Wilmette, 5 boys from​ Winnetka, 4 girls from​ Winnetka, 4 boys from​ Glencoe, and 4 girls from Glencoe. If the teacher calls upon a student to answer a​ question, what is the probability that the student will be a​ boy

Answer 1

9/24

Explanation:

Answer 2

Probability that a boy will answer the question =
`(4)/(7)`

Explanation:

In a certain class of students,

Number of boys from Wilmette = 11

Number of boys from Winnetka = 5

Number of boys from Glencoe = 4

Total boys in the class = 11 + 5 + 4 = 20

Similarly, total number of girls in the class = 7 + 4 + 4 = 15

Total number of students in the class = 20 + 15 = 35

Now number of ways we can choose 1 boy out 20 boys

=
`^(20)C_(1)=20`

Similarly number of ways, we can choose a boy out of 35 students =
`^(35)C_(1)=35`

Now the probability that a boy will answer the question =
`(20)/(35)`

=
`(4)/(7)`