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?
Correct Answer: Option: 1
Let the cost prices of a pen and a books be x and y respectively.
From 1st condition,
0.95x + 1.15y = x+y+7 ... (1)
From 2nd condition,
1.05x + 1.1y = x + y +13 ... (2)
Solving both (1) and (2) for y, we get y=80.
CAT Online Course
Also Check: 841+ CAT Quant Questions with Solutions