Question

Andrew has a bag that contains 8 blue marbles, 6 red marbles, and 10 green marbles. He selects a marble, replaces it in the bag, and then selects another. What is the probability that the first marble is blue and the second marble is red?
A. 1/2
B. 7/12
C. 1/8
D. 1/12

Answer 1

Andrew has 8 blue marbles, 6 red, and 10 green.

8+6+10 = 24 marbles in total.

If he selects a marble, replaces it in the bag, and then selects another, we're being asked the probability that the first marble is blue and the second is red.

You have a 6/24 (1/4) chance of the first one being red.

So you have a 8/24 (1/3) chance of the second being blue.

Since replacement occurs, we multiply them together:

1/4 * 1/3 = 1/12.