Question 38

Mathematics Probability Hard

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 at random, then the probability that 2 white and 1 black balls will be drawn is

(A) \( \frac{13}{32} \)
(B) \( \frac{1}{4} \)
(C) \( \frac{1}{32} \)
(D) \( \frac{3}{16} \)
View Dynamic Solution & Explanation
Correct Solution: Option A

Step-by-step Solution:

Let box A, box B, and box C be the three boxes, respectively. The given event is a Compound Event which can be written as: \[ [(1G \text{ from box A}) \text{ and } (1R \text{ from box B}) \text{ and } (1R \text{ from box C})] \] or \[ [(1R \text{ from box A}) \text{ and } (1G \text{ from box B}) \text{ and } (1R \text{ from box C})] \] or \[ [(1R \text{ from box A}) \text{ and } (1R \text{ from box B}) \text{ and } (1G \text{ from box C})] \] Thus, the probability is: \[ P = \left(\frac{{{}^1C_1}}{{{}^4C_1}} \times \frac{{{}^2C_1}}{{{}^4C_1}} \times \frac{{{}^1C_1}}{{{}^4C_1}} \right) \]\[+ \left(\frac{{{}^3C_1}}{{{}^4C_1}} \times \frac{{{}^2C_1}}{{{}^pC_1}} \times \frac{{{}^1C_1}}{{{}^pC_1}} \right) + \left(\frac{{{}^3C_1}}{{{}^4C_1}} \times \frac{{{}^2C_1}}{{{}^4C_1}} \times \frac{{{}^3C_1}}{{{}^4C_1}} \right) \] \[ P = \left(\frac{1}{4} \times \frac{2}{4} \times \frac{1}{4} \right) + \left(\frac{3}{4} \times \frac{2}{4} \times \frac{1}{4} \right) + \left(\frac{3}{4} \times \frac{2}{4} \times \frac{3}{4} \right) \] \[ P = \frac{2}{64} + \frac{6}{64} + \frac{18}{64} \] \[ P = \frac{26}{64} \] \[ P = \frac{13}{32}. \]