Tom decides to buy some shirts from his favorite fandoms because there is a sale on his favorite website. He buys 5 t-shirts from each of his 4 favorite fandoms. The shirts normally cost $15 each but there is a 20% off sale.  The order qualified for free shipping but he still needed to pay 10% tax. How much did he pay? Give me reasons, before answering the question
He bought 5 * 4 = 20 shirts. The discount saves him 15 * .2 = $3 per shirt. So each shirt cost 15 - 3 = $12. So the total order cost 20 * 12 = $240. Tax added 240 * .1 = $24. So he paid 240 + 24 = $264. So the final answer is 264.