A dishonest shopkeeper declares that he sells his items at cost price, but actually, he uses a false weight of 800 gm for 1 kg. His gain percent is,
25%
Let the cost price of 1kg of goods = ₹ 100
So, the actual cost price = cost price of 800 gm of goods = ₹ 80
The selling price of 1 kg of goods = ₹ 100
So by definition,
Profit = ₹(100-80) = ₹ 20
Profit%=profitCost price×100
Profit%=2080×100
=25%