Probability Ques 22
Question-
A bag contains 2 red, 3 green and 2 blue balls. 2 balls are to be drawn randomly. What is the probability that the balls drawn contain no blue ball?
(1) $\frac{5}{7}$
(2) $\frac{10}{21}$
(3) $\frac{2}{7}$
(4) $\frac{11}{21}$
(5) None of these
(IBPS Bank PO/MT CWE-VII (Prelim Exam) 14.10.2017)
Show Answer
Correct Answer: (2)
Solution: (2)
Total possible outcomes $=$ selection of 2 balls out of 7 balls $={ }^{7} C_{2}$
Total favourable outcomes $=$ slection of 2 balls out of 5 (red + green) balls $={ }^{5} C_{2}$
$\therefore$ Required probability $=\frac{{ }^{5} C_{2}}{{ }^{7} C_{2}}=\frac{5 \times 4}{7 \times 6}=\frac{10}{21}$
BETA
