Probability Ques 7
Question-
In a class, $30 \%$ of the students offered English, 20% offered Hindi and $10 \%$ offered both. If a student is selected at random, what is the probability that he has offered English or Hindi?
(1) $\frac{2}{5}$
(2) $\frac{3}{4}$
(3) $\frac{3}{5}$
(4) $\frac{3}{10}$
(5) None of these
(SIDBI Officer Online Exam.24.02.2016)
Show Answer
Correct Answer: (1)
Solution: (1)
$P(E)=\frac{30}{100}=\frac{3}{10}$;
$P(H)=\frac{20}{100}=\frac{1}{5}$
$P(E \cap H)=\frac{10}{100}=\frac{1}{10}$
$\therefore \quad P(E$ or $H)=P(E \cup H)$ $=P(E)+P(H)-P(E \cap H)$ $=\frac{3}{10}+\frac{1}{5}-\frac{1}{10}=\frac{4}{10}=\frac{2}{5}$
BETA
