Math CentralQuandaries & Queries


Question from Hemantee, a parent:

A fishmonger bought 150kg of fish. he sold 70% of it at the price of Rs90 per kg and the rest at Rs 75 per kg. he made a profit of 42.5 per cent. how much did he pay for the fish.


Suppose that the fish was sold to him at Rsx per kg then the total cost was

cost = 150 × Rsx

He sold 70% of the 150kg for Rs90 per kg so his revenue was

revenue = 0.70 × 150 kg × Rs90/kg

Hence his profit in Rs was

revenue - cost.

Profit as a percentage is usually expressed as a percentage of revenue and thus if his profit is 42.5% of his revenue then

[(revenue - cost)/revenue] × 100 = 42.5.

Solve for x.


About Math Central


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.
Quandaries & Queries page Home page University of Regina PIMS