Question

On selling a pen at 5% loss and a book at 15% gain, Karim gains Rs. 7. If he sells the pen at 5% gain and the book at 10% gain, he gains Rs. 13. What is the cost price of the book in Rupees?

• A. 80
• B. 85
• C. 95
• D. 100

Answer 1

The Correct Option is A

Let x and y represent the cost prices of a pen and a book, respectively.
The first condition is expressed as 0.95x + 1.15y = x + y + 7 ...... (i)
The second condition is expressed as 1.05x + 1.1y = x + y + 13 ....... (ii)
Solving equations (1) and (2) together for y results in y = 80.