when you find the probability of an event happening by subtracting the probability of the event not happening from 1, we are usning
When finding the probability of an event happening by subtracting the probability of the event not happening from 1, we are using the concept of complementary probability.
Complementary probability states that for any event, the probability of that event happening plus the probability of that event not happening is equal to 1. In other words, if an event has a certain probability of occurring, then the probability of the event not occurring is equal to 1 minus the probability of the event occurring.
So, when we need to find the probability of an event happening, we can subtract the probability of the event not happening from 1. This allows us to determine the likelihood of the event occurring without directly calculating its probability.
For example, if the probability of event A occurring is 0.7, then the probability of event A not occurring would be 1 - 0.7 = 0.3. Thus, the probability of event A happening is 0.7.
It's important to note that this method assumes that the event and its complement are mutually exclusive, meaning they cannot both occur at the same time. Additionally, it assumes that the probability of the event not happening is known.