In a certain class of students there are 11 boys from wilmet

In a certain class of students, there are 11 boys from wilmette, 4 girls from Winnetka, 7 girls from wilmette, 4 boys from Glencoe, 5 boys from Winnetka 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?

Solution

Solution:

Total students in class=11+4+7+4+5+4 =35

Total boys=11+4+5 =20

selcting a boy from 20 boys is 20 C1

probababilty=favourable cases/total case

probability ( that the student will be boy)=20_c1/35_{c1 =} 20/35=0.5714 =57.14%