Question

An urn A contains 8 black and 5 white balls. A second urn B contains 6 black and 7 white balls.A blindfolded person is asked to draw a ball selecting one of the urns, the probability that the ball drawn is black is

• A. $\frac{5}{13}$
• B. $\frac{6}{13}$
• C. $\frac{7}{13}$
• D. $\frac{9}{13}$

Answer 1

Answer: (C)

$\frac{7}{13}$

The Probability $=\frac{1}{2}(\frac{8}{13}+\frac{6}{13})=\frac{7}{13}$