RAS question
By selling an article for ₹690, a shopkeeper gains 15%. The cost price of the article is:
Correct answer: (A) ₹600.
When an article is sold for Rs 690 at a 15% gain, its cost price is Rs 600.
Explanation
The selling price is Rs 690 and the gain is 15%, so the selling price is 115% of the cost price. The cited profit-and-loss formula gives cost price as selling price multiplied by 100 divided by 100 plus gain percentage. Substituting the values, cost price = 690 x 100 / 115 = 690 / 1.15 = Rs 600. This is why option A is the only value that fits the condition: if the article originally cost Rs 600, adding a 15% gain makes the selling price Rs 690.
Why the other options are wrong
- (B) Rs 580 is too low because a 15% gain on Rs 580 gives a selling price of Rs 667, not Rs 690.
- (C) Rs 620 is too high because a 15% gain on Rs 620 gives a selling price of Rs 713, not Rs 690.
- (D) Rs 650 is too high because a 15% gain on Rs 650 gives a selling price of Rs 747.50, not Rs 690.
Concept
This tests the profit-and-loss relation between cost price, selling price and gain percentage. It recurs in RAS reasoning and mental ability because percentage-based commercial arithmetic is a standard speed-and-accuracy area.