Melissa collects data on her college graduating class. She finds out that of her classmates, 60% have brown hair, 20% have blue eyes, and 5% have brown hair and blue eyes. What is the probability that one of Melissa's classmates will have brown hair or blue eyes?

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $36.98. find the probability that a randomly selected bill will have an amount greater than $173, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?