Question

A bag contains 4 g r e e n marbles, 8 b l a c k marbles, and 7 b l u e marbles. If a marble is drawn from the bag, replaced, and another marble is drawn, what is the probability of drawing first a g r e e n marble and then a b l u e marble

Answer 1

`P(Green\ and\ Blue) = 0.0776`

Explanation:

Given

`Green = 4`

`Black = 8`

`Blue=7`

Required

Determine the probability of selecting green then blue marble

This probability is represented as:

`P(Green\ and\ Blue)`

And it is calculated using:

`P(Green\ and\ Blue) = P(Green) * P(Blue)`

`P(Green\ and\ Blue) = (n(Green))/(Total) * (n(Blue))/(Total)`

Total marble is:

`Total = 4 + 8 + 7`

`Total = 19`

So, we have:

`P(Green\ and\ Blue) = (4)/(19) * (7)/(19)`

`P(Green\ and\ Blue) = (4*7)/(19*19)`

`P(Green\ and\ Blue) = (28)/(361)`

`P(Green\ and\ Blue) = 0.0776` -- approximated

Hence, the required probability is approximately 0.0776