A bag contains 22 blue, 11 red, and 33 green marbles. You choose one marble. Without putting it back, you choose a second marble. What is the probability that you first choose a green marble and then a blue marble?
First, the probability of getting a green marble first is 33/66 or 1/2, then the probability of getting a blue marble after that is 22/65. So (1/2)*(22/65)=11/65. So the probability is 11/65.