2020 · Q40
A person sold an article for Rs. 75 which cost him Rs. x. He finds that he realised x% profit on his outlay. What is x equal to?
Elementary MathematicsProfit and Loss
- A50
- B25
- C75
- D100
Explanation
Selling price = cost*(1+profit/100): 75 = x(1+x/100), i.e. x^2+100x-7500 = 0, whose positive root is x = 50. Check: 50% of Rs. 50 is Rs. 25, and 50+25 = 75. Note some published keys mark (C) 75, but a Rs. 75 cost sold at Rs. 75 earns zero profit, so 75 is algebraically impossible. Hence option (A).