Question

An urn contains one black ball and one green ball. A second urn contains one white and one green ball. One ball is drawn at random from each urn.Find the probability of getting at least one green ball.

• A. $\frac{1}{2}$
• B. $\frac{1}{3}$
• C. $\frac{2}{3}$
• D. $\frac{3}{4}$

Answer 1

The correct option is D $\frac{3}{4}$

Probability of drawing a black ball from urn 1 $=\frac{1}{2}$
Probability of drawing a white ball from urn 2 $=\frac{1}{2}$
Probability of drawing a green ball from any of the urn $=1-\frac{1}{2}\times \frac{1}{2}=1-\frac{1}{4}=\frac{3}{4}$
Option D is true.