Question

If from each of the three boxes containing 3 white and 1 black, 2 white and 2 black, 1 white and 3 black balls, one ball is drawn, then the probability that 2 white and 1 black ball will be drawn is

• A. $\frac{13}{32}$
• B. $\frac{1}{4}$
• C. $\frac{1}{32}$
• D. $\frac{3}{16}$

Answer 1

The correct option is A $\frac{13}{32}$

Balls can be drawn in the following way
WWB or WBW or BWW

i.e., Prob = $\frac{3}{4}.\frac{2}{4}.\frac{3}{4}+\frac{3}{4}.\frac{2}{4}.\frac{1}{4}+\frac{1}{4}.\frac{2}{4}.\frac{1}{4}=\frac{13}{32}$