Question. James buys steaks for buy one get one free. The price is $15 per pound and he buys 20 pounds. How much did he pay for the steaks?
Answer. 150
What step-by-step reasoning justifies that answer?

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Reasoning: He pays for 20 / 2 = 10 pounds of steaks. That cost 10 * 15 = $150.