ProbabilityMedium
Question
Bag A contains 9 white and 8 black balls, while bag B contains 6 white and 4 black balls. One ball is randomly picked up from the bag B and mixed up with the balls in the bag A. Then a ball is randomly drawn from the bag A . If the probability, that the ball drawn is white, is $\frac{p}{q},gcd(p,q) = 1$, then $p + q$ is equal to
Options
A.22
B.23
C.24
D.21
Solution
$\therefore\ P($ Drawn ball is white $) = \frac{3}{5} \times \frac{10}{18} + \frac{2}{5} \times \frac{9}{18} = \frac{48}{90} = \frac{8}{15} = \frac{p}{q}$
$$\therefore p + q = 23$$
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