A man came into a greengrocer’s shop and asked for a pound of apples at one shilling a pound. The greengrocer gave them to him. Then the man asked, “May I take a pound of pears instead of the apples? The price is the same”. The greengrocer gave him a pound of pears, and he gave back to the greengrocer the pound of apples.
He was going to leave the shop when the greengrocer asked him for the money. “The money for what?” asked the man. “Please pay one shilling for the pears”, said the shopkeeper. “But I gave you the apples for the pears”, answered the man. “Well, then pay me one shilling for the apples, please”. “Why must I pay you for the apples? I didn’t take your apples, you still have your apples”. And the man walked out of the shop with the pears in his hand.