You plan to sell inspirational t-shirts as a fundraiser. The wholesale T-shirt company charges you Php 200.00 a shirt for the first 75 shirts. After the first 75 shirts you purchase up to 150 shirts, the company will lower its price to Php 180.00 per shirt. After you purchase 150 shirts, the price will decrease to Php 150.00 per shirt, Write a function that models this situation.