# Question 122b7

Apr 15, 2017

100%-40% = 60%

#### Explanation:

If we are considering the event "It is raining" - there are only two possibilities:

Either: (It IS raining, or it is NOT raining)
The sum of all the probabilities in a given scenario is 100% = 1

Therefore, if the chance of rain is 40%,

then the chance of no rain is 100%-40% = 60%#

$P \left(\text{event does NOT occur") = 1-P("event DOES occur}\right)$