Question

Two urns each contain green balls and blue balls. Urn I contains 4 green balls and 6 blue balls, and Urn II contains 6 green balls and 2 blue balls. A ball is drawn at random from each urn. What is the probability that both balls are blue?
A. 2/51


B. 3/20


C. 1/10



D.4/153

Answer 1

2/10+6/8=8/80=1/10

C.1/10

Answer 2

Answer: B. $\frac{3}{20}$

Step-by-step explanation:

Let A be the event that a blue ball is drawn from urn l and let B be the event that a blue ball is drawn from urn ll.

Then P(A)=$\frac{\text{number of blue balls}}{\text{total balls}}$

$=\frac{6}{10}=\frac{3}{5}$

and P(B)=$\frac{\text{number of blue balls}}{\text{total balls}}$

$=\frac{2}{8}=\frac{1}{4}$

As both the events are independent, thus the probability that both balls are blue =$P(A)\times\ P(B)=\frac{3}{5}\times\frac{1}{4}=\frac{3}{20}$