Q2: The student council at Hillsdale High School is making T-shirts to sell for a fundraiser, at a price of $ 10 10 each. The costs, meanwhile, are $ 9 9 per shirt, plus a one-time setup fee of $ 79 79 . ​Selling a certain number of shirts will allow the student council to cover their costs. ​What will the costs be? How many shirts must be sold?