Question

A shopkeeper buys paper at Rs 50 per ream. To gain 20%, the selling price per quire will be (take 1 ream = 20 quires)
A) Rs 1
B) Rs 2
C) Rs 3
D) Rs 5

Answer 1

Hint:To solve this problem first of all get the relation between queries and price. Such that you will be able to find the price of 1 quire. Once you find the price of 1 quire, find the selling price at 20 percent gain.

Complete step-by-step solution:
In this problem it is given that the per ream the price is Rs 50
And 1 ream = 20 quires
The shopkeeper buys paper at Rs 50 per ream
1 ream=20 quires (given)
That means
20 quires he buys at Rs 50
So the cost price of 1 quire is
1 quire he buys at \[ = Rs\dfrac{{50}}{{20}}\]
Or,
1 quire he buys at \[ = {\text{ }}Rs{\text{ }}2.5\]
In this question it is asked that the selling price of per quire to get 20 % gain
To gain 20 percent, selling price per quire = the cost price of one quire + 20 % of on quire
The above statement in mathematical form we can write like
=Rs \[\left( {\dfrac{{50}}{{20}} + \dfrac{{20}}{{100}} \times \dfrac{{50}}{{20}}} \right)\]
\[\begin{gathered}
   = Rs\left( {2.5 + 0.2 \times 2.5} \right) \\
   = Rs(2.5 + 0.5) \\
\end{gathered} \]
= Rs 3

Hence to gain 20% by the shopkeeper each quire needs to be sold at Rs 3.

Note: Students keep in mind that this question asks for 20% gain per quire so we need to find the selling price of one quire instead of the total price. Sometimes what happens is students find the gain in the selling price of all queries and get the wrong answer.