Question

If the probability of an event happening is x, then the probability of event not happening is___

• A. 1 - x
• B. x - 1
• C. x + 1
• D. 1/x

Answer 1

The correct option is A

1 - x

If E and $\overline{E}$(not E) are the complementary events, then, we have, P(not E) = 1 - P(E), where P(E) is the probability of happening of event E.

Thus if the probability of an event happening is x, then the probability of the event not happening is 1 - x.