Question

Cindy has two bags

In the first bag there are 3 red balls and 7 green balls
in the second bag there are 4 red balls and 5 green balls
Cindy takes at random a ball from the first bag
She then takes at random a ball from the second bag
a) Complete the probability tree diagram
first bag
second bag
red
10
red
green
b) What is the probability that
Cindy takes two balls of the
same colour?
10
90
red
green
(2)
10
green
green
(2)
Total marks: 4
Bubmit Answer

Answer 1

Explanation:

b) 47

Answer 2

Explanation:

There are a total of 10 balls in the first bag, so P(1 red) = 3/10 and P(1 green) = 7/10.There are a total of 9 balls in the second bag, so P(2 red) = 4/9 and P(2 green) = 5/9.P(1 red & 2 red) = 3/10 × 4/9 = 12/90 = 2/15P(1 red & 2 green) = 3/10 × 5/9 = 15/90 = 1/6P(1 green & 2 red) = 7/10 × 4/9 = 28/90 = 14/45P(1 green & 2 green) = 7/10 × 5/9 = 35/90 = 7/18

I hope you understand it!