Question

A bag contains 8 blue marbles 6 red marbles and 4 green marbles what is the probability of selecting a blue marble replaced it in the bag and then selecting a red marble

Answer 1

`(4)/(27)`

Explanation:

A bag contains 8 blue marbles 6 red marbles and 4 green marbles, 8 + 6 + 4 = 18 marbles in total.

The probability of selecting a blue marble is

`P(\text{blue marble})=\frac{\text{Number of blue marbles}}{\text{Total number of marbles}}=(8)/(18)=(4)/(9)`

Then the blue marble was replaced in the bag.

The probability of selecting a red marble is

`P(\text{red marble})=\frac{\text{Number of red marbles}}{\text{Total number of marbles}}=(6)/(18)=(1)/(3)`

The probability of selecting a blue marble replaced it in the bag and then selecting a red marble is

`P=(4)/(9)\cdot (1)/(3)=(4)/(27)`