Question

Given the probability p=13/20 that an event will not happen, how do you find the probability that the event will happen?

Answer 1

`1-13/20= 7/20`

Explanation:

For any given event, there are only two outcomes:
Either the event DID happen or it DID NOT happen.
(It cannot almost happen, or half happen)

The sum of the probabilities in a given situation is always `1`

`P("event happens") +P("even does not happen") = 1`

`P("even does happen") = 1 - P("even does not happen")`

`P("even does happen") = 1-13/20= 7/20`