Q. Jay and Vijay spent an equal amount of money to buy some pens and special pencils of the same quality from the same store. If Jay bought 3 pens and 5 pencils, and Vijay bought 2 pens and 7 pencils, then which one of the following is correct ?
(a) A pencil costs more than a pen.
(b) The price of a pencil is equal to that of a pen
(c) The price of a pen is two times the price of a pencil
(d) The price of a pen is three times the price of a pencil
Correct Answer: (c) The price of a pen is two times the price of a pencil
Question from UPSC Prelims 2021 CSAT Paper
Explanation :
Jay and Vijay spent an equal amount of money
Let’s say the price of a pen is x and the price of a pencil is y.
Since Jay and Vijay spent an equal amount of money, we can write an equation to represent this: 3x + 5y = 2x + 7y.
Solving this equation for x and y, we get: 3x + 5y = 2x + 7y
3x – 2x = 7y – 5y ; x = 2y
This means that the price of a pen is two times the price of a pencil. So the correct answer is © The price of a pen is two times the price of a pencil.