Suppose that x is an event, and that p(x) = 0.78 what is p(x)

Question

i.e the probability that x will not occur

Answer 1

The probability is 100% that either event X will happen or not. The equation p(x)=0.78 means event X happens 78% of the time. Then the percent of the time that X doesn't happen is 100%-78%=22%=0.22.

In probability this is usually stated as:

P(X)+P(not X)=1.