CORRECT ANSWER: $100
Explanation: The man started by stealing a $100 bill, which is what the shop owner lost. Then, the man used that $100 to buy $70 worth of items, leaving the shop owner to give $30 in change from the register to complete the purchase. So, in total, the shop owner gave back $70 in goods and $30 in cash, which adds up to the $100 the man initially gave. However, it’s important to note that the original $100 belonged to the shop owner, so that’s the amount he lost in the end.