RAS question
A dishonest dealer claims to sell goods at cost price but uses a weight of 800 gm instead of 1 kg. His profit percentage is:
Correct answer: (C) 25%.
A dealer who charges for 1 kg but gives only 800 gm makes a profit of 25%.
Explanation
The dealer says he is selling at cost price, so the apparent selling price is the price of 1 kg. In reality, he gives only 800 gm while taking payment for 1000 gm. NCERT's comparing-quantities rules define cost price and selling price, treat profit as the excess of selling price over cost price, and calculate profit per cent as profit divided by cost price, multiplied by 100. Here, the effective cost is the cost of 800 gm and the extra amount charged equals the cost of 200 gm. Therefore, profit per cent = 200/800 × 100 = 25%.
Why the other options are wrong
- (A) 30% would require profit equal to 30% of the 800 gm actually supplied, but the short weight creates only 200 gm profit on an 800 gm cost base.
- (B) 20% wrongly compares the 200 gm shortfall with 1000 gm, whereas profit percentage must be calculated on the cost of the goods actually given, which is 800 gm.
- (D) 15% understates the gain because the dealer receives the price of 1000 gm while incurring the cost of only 800 gm, leaving a 200 gm profit equivalent.
Concept
This tests profit and loss under false weights, a standard comparing-quantities application. It recurs in RAS mental ability because it checks whether candidates use the actual cost base, not the stated sale quantity.