A bag contains three red marbles, six blue marbles, and three yellow marbles. What is the probability of selecting one red marble, replacing it, and then selecting one blue marble?

A bag contains three red marbles, six blue marbles, and three yellow marbles.

therefore total no. of marbles = 3 + 6 + 3 = 12

total no. of red marble = 3

therefore probablity of selecting one red marble is 3/12 = 1/4

again total no. of blue marbles is 6

therefore probability of selecting one blue marble is 6/12 = 1/2

now total probability of selecting one red ball replacing it then selecting one blue marble is. 1/4 * 1/2 = 1/8