When you are determining the probability of an event, why must the probability be between 0 and 1? Explain your answer.

Answer 1

Probability is the ratio of the desired outcomes to all possible outcomes.

If there are no desired outcomes, the ratio is 0 over all possible outcomes, thus 0.

If the event is all possible outcomes, the ratio is all possible outcomes over all possible outcomes, thus 1.

Answer 2

When you are determining the probability of an event, why must the probability be between 0 and 1? Explain your answer.