A shopkeeper cheats to the extent of 22% while buying and selling fruits, by using tampered weights. His total gain, in percentage is:

With tampered weights he receives 1220 g when buying 1 kg, and gives only 780 g when selling 1 kg. Every 780 g sold earns the price of 1000 g, so his money grows by a factor of 1220/780 = 1.5641 – a gain of about 56.41%.