Question

A SHOPKEEPER BUYS A CERTAIN AMOUNT OF PENS. IF THE SELLING OF 5 PENS IS EQUAL TO THE COST PRICE OF 7 PENS ,FIND HIS PROFIT OR LOSS WITH HIS PROFIT OR LOSS PERCENTAGE .

Answer 1

Answer:

The Profit % made by the shopkeeper is 40%.

Step-by-step explanation:

Given :

Selling Price of 5 pens = Cost Price of 7 pens

To find :

His loss/profit and loss/profit %

Solution :

Consider the Cost Price of one pen as x

Cost Price of 7 pens = Rs. 7x

$\bigstar \: {\boxed{\textsf{SP of 5 pens = CP of 7 pens }}}$

Selling Price is 5 pens = Rs. 7x

Selling Price is one pen = $\tt{\dfrac{7x}{5}}$

$\sf{x < \dfrac{7x}{5}}$

Cost Price < Selling Price

$\therefore$ Its a Profit !

$\rule{300}{1.5}$

$\bigstar{\boxed{\textsf{Profit = Selling price - Cost price}}}$

$\sf{\implies} \: \dfrac{7x}{5} - x \\ \\ \sf{\implies} \: \dfrac{7x - 5x}{5} \\ \\ \sf{\implies} \: \frac{2x}{5}$

Profit = Rs. $\tt{\dfrac{2x}{5}}$

$\rule{300}{1.5}$

$\bigstar\:{\boxed{\sf\:{Profit\% = \frac{SP - CP}{CP} \times 100}}}$

$\sf{\implies} \:{\sf\:{Profit\% = \dfrac{ \frac{2x}{5} }{x} \times 100}} \\ \\\sf{\implies} \:{\sf\:{Profit\% = \dfrac{ \frac{2x}{5} \times 100 }{x}}} \\ \\\sf{\implies} \:{\sf\:{Profit\% = \dfrac{2x \times 20}{x}}} \\ \\ \sf{\implies} \:{\sf\:{Profit\% = \dfrac{40 \: \cancel{x}}{\cancel{x}}}} \\ \\ \sf{\implies} \:{\sf\:{Profit\% = 40\%}}$

$\therefore$ The Profit % made by the shopkeeper is 40%.