Please help me calculate the inspecting cost. The correct answer is 28800, but I don't know how to get this answer. Thanks a lot :3

Windsor Company manufactures two products, A & B. Each year, the company produces 2,400 units of A that requires 20,000 direct labor hours. It also produces 600 units of B that requires 50,000 direct labor hours. The company inspects one A for every 100 produced, and inspects one B for every 10 produced. The total inspecting costs this year is expected at $100,800. How much of the inspecting costs should be allocated to the A product using ABC costing? (Note: insert your number without $) Answer: 28800