Where can I stay in a hotel for three for one yuan? The price per person per day is 10 yuan, and everyone pays 10 yuan, giving the boss 30 yuan in total. Later the boss gave him a discount.

The original topic was three people staying in a hotel, each of whom paid 10 yuan, making a total of 30 yuan. The boss gave the man a 5 yuan discount to return it. The man secretly left 2 yuan's money and gave each of them 3 yuan, which was equivalent to each of them giving 9 yuan, while the 27 yuan and 2 yuan stolen by the man were 29 yuan. Why is 1 yuan missing?

In fact, this is an old scam and there are logical traps in the algorithm. Analyze the whereabouts, the source of all the money is three people, 30 yuan, and then look at the whereabouts. Among them, 3 yuan gave back three people, the man hid 2 yuan and the boss took 25 yuan, which is plain 30 yuan.

Or as the source of 27 yuan is three people, the boss took 25 yuan, and that person hid 2 yuan, so it is clear. The calculation in the topic is a logical trap caused by confusing the source and destination of money. Does the landlord understand?