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?

Answer 1

The probability of drawing a blue ball from each urn is the probability of drawing a blue ball from the Urn 1 multiplied by the probability of drawing a blue ball from Urn 2.

Answer 2

It is sort of like flipping 2 coins and asking for the chance of getting 2 heads.

The chance of getting a head on Coin 1 is 1/2, and it's the same for Coin 2.

The chance of getting heads on both coins is (1/2) * (1/2) = (1/4)

Answer 3

But in this problem the probability is different for drawing a blue ball because there are different numbers of blue and green balls.

Answer 4

A 2/51
B 3/20
C 1/10
D 4/153

Answer 5

i still do not understand

Answer 6

How many total balls in Urn 1? 6 blue + 4 green = 10

How many are blue? 6 blue

So, the chance of drawing a blue ball out of Urn 1 is:

(# of blue balls) / (total # of balls) = 6 / 10

Answer 7

Does that help? Now you can do the same thing for Urn 2...

find # of blue balls / total balls in Urn 2

Answer 8

but the answer isn't up there ^

Answer 9

what did you get for Urn 2?

Answer 10

1/4

Answer 11

so do i multipy 6/10 and 1/4

Answer 12

Sounds right to me.

So the probability of 2 blues is (6/10) * (1/4) = (6 / 40)

Answer 13

3/20

Answer 14

right :) I didn't see it at first, but once you simplify the fraction, it's there :)

Answer 15

thanks for the help

Answer 16

Glad to help :)