JAMB Mathematics 2018 Paper

Concept: Depreciation reduces the value by a fixed percentage each year, so the machine keeps $90\%$ of its previous value annually.Explanation:At the end of the first year, the machine is worth $90\%$ of ₦20,000.Value after year 1 $= \frac{90}{100} \times 20000 = ₦18,000$.At the end of the second year, it is again worth $90\%$ of its value at the beginning of that year.Value after year 2 $= \frac{90}{100} \times 18000 = ₦16,200$.Answer: ₦16,200, which is option A.