The question sounds straightforward: how much money did the shopkeeper actually lose? Some people immediately answer $200, while others believe the loss is $170 or even $130. The confusion comes from trying to count every transaction separately without considering that the stolen money eventually returned to the register.
To understand the correct answer, follow the money carefully. When the thief first takes the $100 bill, the shop loses $100 in cash. However, when he returns and spends that same bill, the $100 goes back into the register. In exchange, the shopkeeper gives him $70 worth of merchandise and $30 in change. Those are the two losses that remain after the transaction.
The correct answer is $100. The shopkeeper loses $70 worth of goods and $30 in cash, making a total loss of $100. The trick is recognizing that the original stolen bill cannot be counted twice. This clever puzzle demonstrates how easily our minds can be fooled by everyday transactions, especially when the same money changes hands more than once.
