What is propability complement sure?

The probability complement refers to the likelihood of an event not occurring. If the probability of an event happening is denoted as ( P(A) ), then the probability of the event not happening is given by ( P(A') = 1 - P(A) ). This concept is fundamental in probability theory, as it helps to understand the total probability space, where the sum of the probabilities of all possible outcomes equals 1. Thus, knowing the probability of an event allows you to easily calculate the probability of its complement.