How can the probability of an event make predictions

The probability of an event can help make predictions by knowing the chance of something happening and using your knowledge to determine the probability of choosing for example blue on a spinner out of 6 with 4 blues. there is 4 blues and 2 red so you predict it will be on red because there is more of it

The answer is Marco can pass out 15 cups that hold 2.5 ounces of juice.