A telemarketer makes 75 calls a day for 5 days. In order to average 100 calls per day for 10 days, how many calls must the telemarketer make in the following 5 days?

The ACT Mathematics Test contains 60 questions to be answered in 60 minutes.  The hardest ACT math questions (the last 10 to 15 questions) fall into two types: advanced concepts and complex questions. Advanced concepts questions cover what you learn in precalculus and trigonometry. FYI: Students that get into Harvard College have an ACT score of 34–36.