Soul

This year, the student council president has decided to raise funds for the school prom by selling Justin Bieber T-shirts. In the past, they've sold an average of 1500 shirts at about $12 each. This year, they plan to decrease the price of the shirts. Based on student feedback, for every $0.50 decrease in price, 20 more T-shirts will be sold. a) Determine the demand (price) function in terms of the number of t-shirts sold. [4 APP marks]