Suppose you have a bag containing two red marbles, two blue marbles, and two white marbles. You choose two marbles without looking.

Question

a. What is the probability that you will choose a red marble and then a blue marble without replacing the red one?
b. What is the probability that you will choose two red marbles in a row without replacing the first one?

Answer 1

a) 2/6 picking the red and 2/5 picking the blue. (2/6)*(2/5) = 4/30

b) (2/6) picking the red (1/5) picking the second (2/6)*(1/5) = 2/30