Mary is preparing for her college entrance exams. In a practice test, she answered 15 problems in 45 minutes. At this rate, how many problems is she expected to answer in 180 minutes? (Proportional Reasoning)

I really need an answer, and it would be great if you answer

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $32.09. find the probability that a randomly selected bill will have an amount greater than $155, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?