Question

There are 21 girls and 33 boys in a classroom. I want to randomly select one student to become the class leader. If I want to find the probability that the selected student is a girl, the number of favourable outcomes is

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Answer 1

I want to find the probability that a girl is selected. Or, A girl being selected is a favourable outcome. There are 21 girls. In other words, a girl can be selected in 21 ways. Hence the number of favourable outcomes is 21.

Similarly the total number of students is 21 + 33 = 54. Hence a student can be selected in 54 ways. Hence a total number of outcomes is 54.

The correct answer is 21.