James makes potatoes for a group. Each person eats 1.5 pounds of potatoes. He makes potatoes for 40 people. A 20-pound bag of potatoes costs $5. How much does it cost? Give me reasons, before answering the question
He needs 1.5 * 40 = 60 pounds of potatoes. So he needs to buy 60 / 20 = 3 bags of potatoes. So it cost 3 * 5 = $15. So the final answer is 15.