If a farmer earns ₦450,000 from the sale of produce in a season and incurs total production costs of ₦180,000, what is the farmer's profit margin as a percentage of revenue?

Profit = Revenue − Cost = ₦450,000 − ₦180,000 = ₦270,000. Profit margin (%) = (Profit ÷ Revenue) × 100 = (₦270,000 ÷ ₦450,000) × 100 = 60%. Option A (40%) results from dividing cost by revenue; option C (150%) results from dividing profit by cost; option D (250%) is a common arithmetic error from incorrect formula application.