An event that is certain to happen has a probability of 1. An event that cannot possibly happen has a probability of 0. If there is a chance that an event will happen, then its probability is between 0 and 1. For example: If you have 3 dimes and 2 nickels in your pocket, and you reach in your pocket and pull out one coin, then the probability of that coin being a nickel is 2/5. The probability of that coin being a penny is 0, because there are no pennies in your pocket!! If you have 5 nickels in your pocket, and you reach in your pocket and pull out one coin, then the probability of that coin being a nickel is 1, because you have only nickels in your pocket!
