Question

A bag contains five green marbles three blue marbles and two red marbles if two consecutive marbles are drawn without replacement what is the probability that the first world will be green and the second good will be read

Answer 1

`(1)/(9)`

Explanation:

There are 10 marbles in the bag. 5 are green. 3 are blue. 2 are red.

The probability that the first marble would be green is
`(5)/(10)`, or
`(1)/(2)`.

Now, there are 9 marbles in the bag. 4 are green. 3 are blue. 2 are red.

The probability that the second marble would be green is
`(2)/(9)`.

The probability that the first marble is green and the second is red is:

`(1)/(2)` ×
`(2)/(9)` =
`(1)/(9)`.

Answer 2

1 / 9

Explanation:

P(Green) = 5 / 10

P(Blue) = 3 / 10

P(Red) = 2 / 10

These are independent events as one cannot occur at the same time as the other so can multiply their probabilities together

First choice green: 5 / 10

The denominator will decrease because we arent replacing the marbles after we take one out of the bag

Second choice red: 2 / 9

So

5 / 10 x 2 / 9

10 / 90 = 1 / 9