COLLEGE MATH!!!!!

Question

A bag contains 3 blue marbles, 2 red marbles, and 4 yellow marbles. One marble is randomly selected. What is the probability that the marble is blue given that the marble is not yellow?

Answer 1

The first thing to do is eliminate the yellow marbles entirely from the probability. Now you are only dealing with the probability that the marble is red or blue.

Now the probability of the blue marble is the amount of the blue marbles out of the total it could be which is (red+blue).

Answer is

blue/(red+blue)