Question

A bag contains 3 red marbles, 4 white marbles and 5 blue marbles. If one marble is drawn from the bag, what is the probability that the marble will be blue?

Answer 1

There is a 5/12 chance that the marble will be blue. The reasoning behind this is that if you count all the marbles it will equal 12. So then all you have to do is see how many blue marbles there are, put that as the numerator, and put 12 as the denominator.