Question

In a class of 60 boys and 20 girls, half of the boys and half of the girls know cricket, then the probability of the event that a person selected from the class is either a boy or a girl who knows cricket is

• A. $\frac{1}{2}$
• B. $\frac{3}{8}$
• C. $\frac{5}{8}$
• D. $\frac{7}{8}$

Answer 1

Answer: (D)

Step - 1: Find probability of boys and girls knowing cricket
Total number of student $=60+20=80$
Probability of selecting boys $=\frac{60}{80}=\frac{3}{4}$
Number of girls in class $=20$
Numbers of girls knowing cricket $=10$
Probability that selected one is girl knowing cricket $=\frac{10}{80}=\frac{1}{8}$
Step - 2: Find probability
Probability of either boy or girls knowing cricket is
Total probability $=\frac{3}{4}+\frac{1}{8}$
$ \begin{array}{l} =\frac{6+1}{8} \\ =\frac{7}{8} \end{array} $
Hence, the answer is $\frac{7}{8}$.