Question

A shopkeeper sells a pen for rs 20. He makes a profit of 15%. At what price did he buy the pen?​

Answer 1

Given :

• Selling price of the pen = Rs.20
• Profit% = 15%

To Find :

• The cost price of the pen

Solution :

Profit% of an article is given by ,

$\\ \star \: {\boxed{\purple{\sf{profit\% = \frac{(SP - CP)100}{CP} }}}}$

Here ,

• SP and CP are selling price and cost price of the article

We have ,

• SP = Rs.20
• Profit% = 15%

Substituting the values ,

$\\ : \implies \sf \: 15 = \frac{(20 - CP)100}{CP}$

$\\ : \implies \sf \: 15CP= (20 - CP)100$

$\\ : \implies \sf \: 15CP = 2000 - 100CP$

$\\ : \implies \sf \: 15CP+ 100CP = 2000$

$\\ : \implies \sf \: 115CP = 2000$

$\\ : \implies \sf \: CP= \frac{2000}{115}$

$\\ : \implies{\underline{\boxed{\pink {\mathfrak{CP \approx \: Rs.\:17.39}}}}} \: \bigstar$

$\\ \therefore{\underline{\sf{Hence \: , \: The \: cost \: price \: of \: the \: pen \: is \: \bold{Rs.\:17.39}}}}$