If the probability of an event happening is 2/5, then the probability of the event not happening is 3/5? This is False. The answer is 1/3. Explain why the answer is 1/3
As far as I know the probability of it happening + the probability of it not happening sum to 1. Therefore I believe the answer is 3/5.
To understand why the answer is 1/3, we need to first understand the concept of complementary events.
Complementary events are those that cover all possible outcomes in a given situation. In this case, the event we are considering is "the event happening." The complementary event is "the event not happening," or basically, the opposite outcome.
The probability of an event happening and the probability of its complementary event not happening always add up to 1. In other words:
P(event happening) + P(event not happening) = 1
Given that the probability of the event happening is 2/5, we can denote it as P(event happening) = 2/5. If we substitute this value into the equation above, we get:
2/5 + P(event not happening) = 1
To find the probability of the event not happening, we can rearrange the equation to solve for it:
P(event not happening) = 1 - 2/5
P(event not happening) = 5/5 - 2/5
P(event not happening) = 3/5
Therefore, the probability of the event not happening is indeed 3/5, rather than 1/3. The initial statement "If the probability of an event happening is 2/5, then the probability of the event not happening is 3/5" is true, not false.