A trader buys goods worth ₦150,000 and sells them for ₦195,000. What is the trader's gross profit margin?

Gross profit = ₦195,000 − ₦150,000 = ₦45,000. Gross profit margin = (Gross profit ÷ Sales) × 100 = (₦45,000 ÷ ₦195,000) × 100 ≈ 23.1%. Option C (30%) is the mark-up percentage on cost, a common distractor error.