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.
`(3)/(20)`

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}}`

`=(6)/(10)=(3)/(5)`

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

`=(2)/(8)=(1)/(4)`

As both the events are independent, thus the probability that both balls are blue =
`P(A)*\ P(B)=(3)/(5)*(1)/(4)=(3)/(20)`