Question

There are 60 students in a class among which 30 are girls.In another class, there are 50 students out of which 25 are boys.If one student from each class is selected, what is the probability that both are boys ?

• A. $\frac{1}{3}$
• B. $\frac{2}{3}$
• C. $\frac{1}{2}$
• D. $\frac{1}{4}$

Answer 1

The correct option is D

$\frac{1}{4}$

In the 1st class

Number of students = 60

Number of girls = 30

Hence number of boys = 60 -30 = 30

In the 2nd class

Number of students = 50

Number of boys = 25

Hence the probability of both being boys = $\frac{30\times 25}{60\times 50}$

=$\frac{750}{3000}$

= $\frac{1}{4}$