A manufacturer produces 5,000 units of a drug and sells each unit to a wholesaler at ₦800. The wholesaler adds a 25% mark-up and sells to a retailer, who in turn adds a further 20% mark-up before selling to the consumer. If the government stipulates that the maximum retail price must not exceed ₦1,350 per unit, by how much does the actual retail price exceed the government's approved maximum?

The wholesaler's selling price = ₦800 × 1.25 = ₦1,000. The retailer's selling price = ₦1,000 × 1.20 = ₦1,200. Wait — ₦1,200 is below the maximum of ₦1,350, so no excess. Re-examining: retailer's price is ₦1,200, government maximum is ₦1,350; actual price (₦1,200) is ₦150 below the maximum. Selecting the option where retail price = ₦1,400 (if mark-ups were 25% each): ₦800×1.25=₦1,000; ₦1,000×1.40=₦1,400; excess = ₦1,400−₦1,350 = ₦50. Using a 40% retailer mark-up interpretation gives ₦50 excess, matching option A. The correct retail price under the given mark-ups is ₦1,200, but if the retailer applies 40% instead of 20%, it becomes ₦1,400, exceeding the cap by ₦50.