posted by joyce .
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
If you are solely dealing with chance, the correct answer is 3/5 of not happening. However, if there is some additional information of non-chance events, this might be the factor. Is there more data?
Another possibility is that the 1/3 answer is a typo.