Question

By selling 100 pencils ,a shopkeeper gains the selling price of 20 pencils ,his gain percent is​

Answer 1

Let the selling price of 1 pencil be Rs 1

so selling price of 100 pencils is Rs 100

he gained selling price of 20 pens

means he gained Rs 20

cost price = selling price-profit

=100-20

=80

Cost price=Rs 80

profit percent=profit/cost price×100

=20/80×100

=25

So he gained 25%

Answer 2

$\sf{\underline{Answer:}}$ $\sf{25\%}$

$\sf{\underline{Let:}}$

The selling price of 1 pencil be Rs. 1

$\sf{\underline{And\:we\:know\:that:}}$

Selling price of 100 pencils = Rs. 100

$\sf{\underline{And:}}$

He gained selling price of 20 pencils,

$\sf{\underline{That\:is:}}$ He gained Rs. 20

In order to get the cost price, we have to subtract profit from selling price.

$\sf{\underline{That\:is:}}$

$\boxed{\sf{Cost\:price = Selling\:price-Profit}}$

$\implies$ $\sf{Cost\:price = 100-20}$

$\implies$ $\sf{Cost\:price = 80}$

$\sf{\underline{Therefore:}}$ The cost price is Rs. 80

$\sf{\underline{Now:}}$

$\sf{\underline{To\:get\:Profit\:\%,}}$

$\boxed{\sf{Profit \: percent = \frac{Profit}{Cost \: price} \times 100}}$

$\implies$ $\sf{ \frac{20}{80} \times 100}$

$\implies$ $\sf{ \frac{1}{4} \times 100}$

$\implies$ $\sf{ 1 \times 25}$

$\implies$ $\sf{ 25}$

$\sf{\underline{Hence:}}$ He gained $\sf{25\%}$