WAEC 2019 Mathematics · Question 36

Bala sold an article for #6,900.00 and made a profit of 15%. Calculate his percentage profit if he had sold it for N6,600.00.

Options

A.5%
B.10%
C.12%
D.13%

Answer: B. 10%

Explanation written with AI and checked against the answer key

Analyze the question: Bala sold an article for ₦6,900 and made a 15% profit. We need to find the cost price first, then work out the percentage profit if the selling price were ₦6,600. Concept: Selling Price (SP) = Cost Price (CP) × (1 + profit%) Percentage profit = (SP − CP) / CP × 100 Step 1: Find the cost price 6,900 = CP × 1.15 CP = 6,900 / 1.15 = ₦6,000 Step 2: Find the profit if SP = ₦6,600 Profit = 6,600 − 6,000 = ₦600 Step 3: Percentage profit % profit = (600 / 6,000) × 100 = 10% Answer: The percentage profit is 10%, which is option B. Tip: For "profit of x%" questions, always find the cost price first, because percentage profit is always calculated on the cost price. Dividing the selling price by (1 + profit/100) gives you CP quickly. Here 6,900 ÷ 1.15 gives a neat 6,000, which is a good sign you're on the right track.

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