Probability Ques 8
Question-
A bag contains 13 white and 7 black balls. Two balls are drawn at random. What is the probability that they are of the same colour?
(1) $\frac{41}{190}$
(2) $\frac{21}{190}$
(3) $\frac{59}{190}$
(4) $\frac{99}{190}$
(5) $\frac{77}{190}$
(IBPS Bank PO/MT CWE 17.06.2012)
Show Answer
Correct Answer: (4)
Solution: (4)
Total possible outcomes $=20_{C_{2}}=\frac{20 \times 19}{1 \times 2}=190$
Total favourable outcomes $=13_{C_{2}}+7_{C_{2}}=\frac{13 \times 12}{1 \times 2}+\frac{7 \times 6}{1 \times 2}$ $=78+21=99$
$\therefore$ Required probability $=\frac{99}{190}$
BETA
