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?
A) 0.71
B) 0.429
C) 0.571
D) 0.314

Question

Quizplus · Accepted Answer

The total number of boys is 11 (Wilmette) + 5 (Winnetka) + 4 (Glencoe) = 20. The total number of students is 11 (boys from Wilmette) + 7 (girls from Wilmette) + 5 (boys from Winnetka) + 4 (girls from Winnetka) + 4 (boys from Glencoe) + 4 (girls from Glencoe) = 35. Therefore, the probability of selecting a boy is 20/35 = 4/7 ≈ 0.571.

In a Certain Class of Students, There Are 11 Boys