An antique dealer sold three items, A, B, and C, with their selling prices in the ratio 4:5:6. He suffered a loss of 10% on item A, made a profit of 50% on item B, and broke even (no profit, no loss) on item C. What was his approximate percentage gain or loss in the overall deal?
- (a)loss of 8.88%
- (b)profit of 8.88%
- (c)profit of 10.88%
- (d)loss of 10.88%
Answer
Why
Correct — B. Give the selling prices numbers that divide cleanly: 36, 45, 54 (4 : 5 : 6 × 9).
A, 10% loss: CP = 36 ÷ 0.9 = 40
B, 50% profit: CP = 45 ÷ 1.5 = 30
C, break-even: CP = 54
Total CP = 124, total SP = 135
Profit = 11, and 11 ÷ 124 × 100 = 8.87%
Nearest option: profit of 8.88% → option (b)
Why the others are wrong
- (a)loss of 8.88% — Right size, wrong direction. The total selling price of 135 exceeds the total cost of 124, so the dealer gained on the whole deal.
- (c)profit of 10.88% — That rate on a cost of 124 would need a profit of about 13.5. The actual profit is 135 − 124 = 11, which is 8.87%.
- (d)loss of 10.88% — Wrong on both counts: the deal ends in profit (135 against 124), and its size is 8.87%, not 10.88%.
Concept
When selling prices come in a ratio, recover each item's cost separately: CP = SP ÷ (1 + profit%) or SP ÷ (1 − loss%).
The overall figure is total profit over total cost, not an average of the three percentages. Scaling the ratio by 9 makes both divisions exact: 36 ÷ 0.9 = 40 and 45 ÷ 1.5 = 30.
The exact figure is 11⁄124 = 8.8709…%, which rounds to 8.87%. The option prints 8.88%, and the stem asks for the approximate figure, so the key's profit of 8.88% is the match.
Key facts
- CP = SP ÷ (1 + p⁄100) for a profit of p%, and SP ÷ (1 − l⁄100) for a loss of l%.
- Overall profit % = (total SP − total CP) ÷ total CP × 100.
- With selling prices of 36, 45 and 54, the costs are 40, 30 and 54, totalling 124.
Study next
Common traps
- Averaging the three percentages: (−10 + 50 + 0) ÷ 3 = 13.33%, which matches no option.
- Weighting the percentages by the selling-price ratio: (4 × −10 + 5 × 50) ÷ 15 = 14%. Percentages must be weighted by cost.
- Dropping C because it broke even: its cost of 54 still belongs in the total.
15 Sep 2025, 16:00, Quant Q.12 uses the same frame with mobile covers: selling prices 3 : 4 : 5, profits of 25% and 10% and a 20% loss, so costs of 2.4 + 3.636 + 6.25 = 12.286 against sales of 12, keyed a loss of 2.33%.
Related PYQs
No directly related past PYQ was found.