Required Mathematical Intelligence

Chapter 10 A Counterfeit Money

One evening, a customer came to a body shoe store and bought a pair of cloth shoes with 10 yuan.The pair of shoes is 7 yuan, and it needs to be found by the customer for 3 yuan.Because there was no change, the owner of the shoe store took the 10 yuan to the small shop next door to break it into change and gave the customer 3 yuan. The customer took the money and shoes and left.The next day, someone from the shop next door said yesterday's money was fake, so the boss had to take out 10 yuan and sighed: "Today's loss is too great."Please do the math for him, how much money did he lose in total?
[Answer: I lost 10 yuan, which is the face value of a counterfeit coin.Many people complicate the problem when guessing this question, and instead get the result wrong. ]
(End of this chapter)