Probability Ques 10
Question-
There are 9 red, 7 white and 4 black balls in an bag.
Two balls are drawn at random from the bag. What will be the probability that both the balls are red?
(1) $\frac{18}{95}$
(2) $\frac{9}{95}$
(3) $\frac{9}{10}$
(4) $\frac{8}{95}$
(5) $\frac{5}{19}$
Show Answer
Correct Answer: (1)
Solution: (1)
Total possible outcomes $=$ Selection of 2 balls out of $(9+$ $7+4=) 20$ balls $={ }^{20} C_{2}=\frac{20 \times 19}{1 \times 2}=190$
Favourable outcomes $=$ Selection of 2 balls out of 9 red balls $={ }^{9} C_{2}=\frac{9 \times 8}{1 \times 2}=36$
$\therefore$ Required probability $=\frac{36}{190}=\frac{18}{95}$
BETA
