A bag contains 15 marbles. The probability of randomly selecting a green marble is 1/5. The probability of randomly selecting a green marble, replacing it, and then randomly selecting a blue marble is 2/25. How many blue marbles are in the bag?

2

3

5

6

6 blue marbles

Step-by-step explanation:

Given;

Total number of marbles N = 15

probability of randomly selecting a green marble

P (G) = 1/5

The probability of randomly selecting a green marble, replacing it, and then randomly selecting a blue marble P (G∩B) = 2/25

P (G∩B) = P (G) * P (B)

P (B) = P (G∩B) : P (G)

The probability of selecting a blue marble

P (B) = 2/25 : 1/5 = 2/5

The number of blue marbles N (B) = P (B) * N

N (B) = 2/5 * 15 = 6

There are 6 blue marbles