suppose you choose a marble from a bag containing 3 red marbles, 3 white marbles, and 5 blue marbles. you return the first marble to the bag and then choose again. find p(red then blue).

Since there are 3 marbles that are red out of 11, the probability of picking a red is 3/11. The probability that the next pick will be blue is 5/11.

Multiply those 2 numbers together and you get 3/11 * 5/11 = (3*5) / (11*11) = 15/121