Question

In a college, 25% of the boys and 10% of the girls offer Mathematics. The girls constitute 60% of the total number of students. If a student is selected at random and is found to be studying Mathematics, the probability that the student is a girl, is

• A. 1/6
• B. 3/8
• C. 5/8
• D. 5/6

Answer 1

Answer: (B)

3/8

Answer 2

Let 100 students studying in which 60% girls and 40%

boys.

Boys = 40, Girls = 60

25% of boys offer Maths = $\frac { 25 } { 100 } \times 40 = 10$ Boys

10% of girls offer Maths = $\frac { 10 } { 100 } \times 60 = 6$ Girls

It means, 16 students offer Maths

∴ Required probability = $\frac { 6 } { 16 } = \frac { 3 } { 8 }$