Answer:
25%
Step-by-step explanation:
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%
