Profit & Loss

Fast trick to solve the profit and loss.

If toffee are bought at '30' for a rupee.How many toffee must be sold for a rupee so as to gain '50%'.

Cost price of 30 toffee = Rs. 1

Cost price of 1 toffee = Rs. 1 / 30

gain 50% so

Selling price = 150% = 150 / 100 = 3 / 2

Selling price 1 toffee = 1 / 30 * 3 / 2 = 1 / 20

Selling price 20 toffee = Rs. 1

20 toffee must be sold for a rupee.