Probability Ques 26
Question-
A bag contains 2 yellow, 3 green and 2 blue balls. Two balls are drawn at random. What is the probability that none of the balls drawn is blue?
(1) $\frac{1}{2}$
(2) $\frac{10}{21}$
(3) $\frac{9}{11}$
(4) $\frac{7}{11}$
(5) $\frac{3}{7}$
(IDBI Bank PO Exam 29.04.2018)
Show Answer
Correct Answer: (2)
Solution: (2)
Total number of balls in the bag $=2+3+2=7$
Two balls are taken out.
$\therefore$ Total possible outcomes $={ }^{7} C_{2}=\frac{7 \times 6}{1 \times 2}=21$
No ball is blue
$\therefore$ Favourable outcomes $=$ Selection of 2 balls out of remaining 5 balls $={ }^{5} C_{2}=\frac{5 \times 4}{1 \times 2}=10$
$\therefore$ Required probability $=\frac{10}{21}$
BETA
