1 Considering that the total amount of material (money) remains unchanged, what Lao Wang loses is equal to what he loses minus what he gets. As follows:

What Lao Wang got: 100 yuan counterfeit money given by young people+100 yuan real money borrowed by neighbors.

Lao Wang pays: (18 yuan costs young people to take +79 yuan real banknotes to young people) +( 100 yuan real banknotes to neighbors+100 yuan counterfeit banknotes to neighbors).

So in the whole transaction process, what Lao Wang lost is equal to what he paid MINUS what he got:

Finally: 97 yuan!

During the whole transaction, among the three people, the neighbors did not get or lose, and the total amount of material (money) did not drain. So what Lao Wang lost was what young people got, and what young people got was:

Cost +79 yuan real money =97 yuan.

So what Lao Wang lost was: 97 yuan.

Suppose the young man gave Lao Wang real money, and the money Lao Wang earned in the whole transaction was: 2 1- 18=3 yuan. Then, 100 yuan of counterfeit money is equivalent to Lao Wang's loss of 100 yuan, MINUS the earned 3 yuan, so Lao Wang lost * * *:

100-3=97 yuan.