Question

In a certain class of students, there are 8 boys from Wilmette, 4 girls from Winnetka, 10 girls from Wilmette, 5 boys from Glencoe, 3 boys from Winnetka and 7 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

`(16)/(37)\approx0.432`

Explanation:

BOYS

• 8 boys from Wilmette
• 5 boys from Glencoe
• 3 boys from Winnetka

GIRLS

• 4 girls from Winnetka
• 10 girls from Wilmette
• 7 girls from Glencoe

Total Number of Boys n(B)= 8+5+3=16

Total Number of Girls, n(G)=4+10+7 =21

Total Number of students, n(S) =21+16 =37

If a student is called randomly to answer a question,

P(Student will be a boy)

`=(n(B))/(n(S)) \\=(16)/(37)\approx0.432`

Answer 2

43.24% probability that the student will be a boy

Explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

Desired outcomes:

Student being a boy.

8 boys from Wilmette

5 boys from Glencoe

3 boys from Winnetka

So
`D = 8+5+3 = 16`

Total outcomes:

All students

`T = 8+4+10+5+3+7 = 37`

Probability:

`p = (D)/(T) = (16)/(37) = 0.4324`

43.24% probability that the student will be a boy