Probability Ques 12
Question-
There are 9 red, 7 white and 4 black balls in an bag. In a bag there are 5 red, 6 blue, 2 green and 7 white balls. Two balls are drawn at random. What is the probability that both the balls are of blue colour?
(1) $\frac{2}{17}$
(2) $\frac{1}{19}$
(3) $\frac{1}{2}$
(4) $\frac{3}{38}$
(5) None of these
(United Bank of India PGDBF Manipal Exam,07.08.2016)
Show Answer
Correct Answer: (4)
Solution: (4)
Total number of balls $=5+6+2+7=20$
Total possible outcomes $=$ Selection of 2 balls out of 20 balls $=$ $20_{C_{2}}$ $=\frac{20 \times 19}{1 \times 2}=190$
Favourable outcomes $=$ Selection of 2 balls out of 6 blue balls $=6_{C_{2}}=\frac{6 \times 5}{1 \times 2}=15$
$\therefore$ Required probability $=\frac{15}{190}=\frac{3}{38}$
BETA
