Question

a bag contains 10 red marbles, 15 blue marbles, and 5 green marbles. what is the probability of randomly drawing a red marble, then a blue marble, without replacement?

Answer 1

`(5)/(29)`

Explanation:

Drawing a red marble:

n(S) = 10 + 15 +5 = 30

n(red) = 10

P(red) =
`(10)/(30)`

=
`(1)/(3)`

Drawing a blue marble after the red marble:

n(S) = 9 + 15 + 5 = 29

n(blue) = 15

P(blue) =
`(15)/(29)`

P(blue | red) =
`(1)/(3) *(15)/(29)`

=
`(5)/(29)`