WAEC 2021 Mathematics · Question 24

A trader paid import duty of 38 kobo in the naira on the cost of an engine. If a total of #22,800.00 was paid as import duty, calculate the cost of the engine.

Options

A.#60,000.00
B.#120,000.00
C.#24,000.00
D.#18,000.00

Answer: A. #60,000.00

Explanation written with AI and checked against the answer key

Analyze the question Import duty is charged at 38 kobo for every naira of the engine's cost. Since 100 kobo = ₦1, the duty rate is 38/100 = 38%. We know the duty paid (₦22,800) and need the cost of the engine. Concept Import duty = rate × cost So, Cost = Duty ÷ Rate Solution Duty = 0.38 × Cost 22,800 = 0.38 × Cost Cost = 22,800 ÷ 0.38 Cost = 22,800 × 100 ÷ 38 Cost = 600 × 100 (since 22,800 ÷ 38 = 600) Cost = ₦60,000 Check: 0.38 × 60,000 = 22,800 ✓ Answer: The cost of the engine is ₦60,000.00, which is option A. Tip: "Kobo in the naira" simply means a percentage, because there are 100 kobo in ₦1. So 38k in the naira = 38%. When you know the part (the duty) and need the whole (the cost), divide the part by the rate. A quick check by multiplying back will confirm your answer.

AI can make mistakes. Report anything that looks wrong.