Mathematics for IGCSE & O level - Probability (Section 5 - No. 12)

A bag contains 5 red, 4 blue, and 3 green marbles. What is the probability of selecting a marble that is NOT blue?

1/3

5/12

3/4

7/12

There are 5+3 = 8 marbles that are not blue. Probability = 8/12 = 2/3 = 4/6. Option 4,7/12 is the closest answer and should be correct.