Answer:
Probability that a boy will answer the question = [tex]\frac{4}{7}[/tex]
Step-by-step 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
= [tex]^{20}C_{1}=20[/tex]
Similarly number of ways, we can choose a boy out of 35 students = [tex]^{35}C_{1}=35[/tex]
Now the probability that a boy will answer the question = [tex]\frac{20}{35}[/tex]
= [tex]\frac{4}{7}[/tex]
