Question

By selling 20 pens, a shopkeeper gains equal to the selling price of 4 pens. Calculate his gain percent.

Answer 1

Given:

By selling 20 pens, a shopkeeper 's gain is equal to the selling price of 4 pens.

So,

20 ( Selling price -  Cost price ) =  4 Selling price

5 ( Selling price -  Cost price ) =   Selling price

5 Selling price -  5 Cost price   =  Selling price

4 Selling price  =  5 Cost price

Selling price = 5 cost price / 4

So,

Gain  =  Selling price  -  Cost price  = 5 Cost price/4  - Cost price 

= 5 Cost price − 4 Cost price / 4 

= 1/4 Cost price

Gain % 

= 1/4 Cost price / Cost price×100 = 100/4 = 25 %   


ANSWER= 25%

Answer 2

Answer =20

loss%=loss/ c.p× 100

= 4/20×100

=20