Question

If P(not event B) = 0.95, what is P(event B)?

Answer 1

Answer is 0.05

The two events of B happening, or B not happening, are complementary events. One or the other must happen. There is no overlap so both events cannot happen simultaneously. This means the two probabilities add to 1, which represents 100%

P(event B) + P(not event B) = 1

P(event B) = 1 - P(not event B)

P(event B) = 1 - 0.95

P(event B) = 0.05

Answer 2

0.05

Explanation:

To find P(event b) you would do 1- P(not event B) which in this problem would be seen as 1-(0.95)= 0.05