Question

In a class, 30% of the students are male and 70% female. Among male students, 40% wears eye glasses; among female students, 30% wear eye glasses. If we select a student from the class at random, what is the probability that the student wears eye glasses?

Answer 1

33%.

Explanation:

Suppose there are 100 students in the class.

Number of males wearing glasses = 30 * 0.40 = 12.

Number of females wearing glasses = 70 * 0.30 = 21.

Required probability = (12 + 21) / 100

= 33/ 100

= 33%.