Question

The probability of an event happening is 0.13, what will be the probability of the event not happening?

• A. 0.87
• B. 0.54
• C. 0.23
• D. 0.34

Answer 1

The correct option is A 0.87

There are always two possibilities with an event, either it will happen or it will not happen.

We know that the sum of probabilities of all possible outcomes of an event is 1.

$\therefore$ The sum of probabilities of an event happening and an event not happening = 1

Let P(E) be the probability of an event happening.
(Then, P(not E) is the probability of the event not happening)

Then, P(E) = 0.13 (Given)
$\Rightarrow$ P(not E) = 1 – 0.13 = 0.87