How Much is the Loss?

A cheat goes to a footwear shop and buys a product for 12 dollars paying with a 20 dollar note. As the seller did not have necessary change, he changes it from the next door shop and gives the cheat the balance 8 dollar and the product. After certain time, the second shop owner returns the 20 dollar note, saying that it is counterfeit. Now the poor first seller has to shell out another 20 dollar to the second shop owner. Besides, for nothing, he has sold the product whose value is 12 dollar and also gave the balance 8 dollar to the cheat. Now the question is how much is the exact loss incurred to the shop owner?

Answer:

Many people fall prey to this simple, beautiful problem saying that the loss is only 40. Because the shop owner has sold the cheat the product whose value is 12 and also given him 8, besides he has to pay another 20 to the second shop owner. Some might think that the loss is only 32, because he had returned the balance 8, not from his own pocket but from the change given by the second shop owner. Therefore 40-8=32 is the actual loss. To cut the long story short, the loss is only 20 dollars. You forget the story of second shop owner's transaction and try to think afresh in the following way: For a counterfeit 20 dollar, he had delivered the product (value 12 dollors) and lost 8 by way of giving him the balance.