A bag contains 8 red marbles, 4 blue marbles, and 1 green marble. What is the probability of choosing a marble that is not blue when one marble is drawn from the bag?
There are a total of 8 red marbles, 4 blue marbles, and 1 green marble, so there are a total of 13 marbles in the bag.
The probability of choosing a marble that is not blue is given by the number of favorable outcomes divided by the total number of possible outcomes.
The number of favorable outcomes is the number of marbles that are not blue, which is 8 red marbles + 1 green marble = 9 marbles.
The total number of possible outcomes is the total number of marbles in the bag, which is 13 marbles.
Therefore, the probability of choosing a marble that is not blue is 9/13.