Question

The table below shows the breakdown of marbles in a bag. What is the probability of choosing a red OR blue marble? Answer as a simplified fraction.

Color # Marbles
Red
8
Blue
12
Green
4
Black
6
Total
30

Answer 1

The probability is the ratio of "number of possible desired outcomes" over "number of all possible outcomes."

There are 30 marbles in total.

There are 8 red and 12 blue, so there are 20 marbles that are either red or blue. So the chance of picking a red or blue marble is 20/30 or 2/3.