Mathematics for IGCSE & O level - Probability (Section 4 - No. 1)

If the probability of an event occurring is 0.25, what is the probability of that event *not* occurring?

0.25

0.5

0.75

1.0

The probability of an event not occurring is 1 minus the probability of the event occurring. Therefore, 1 - 0.25 = 0.75