answer: #Person1# introduces the guide information to #Person2#.
documents: #Person1#: Do you need a guide?
  #Person2#: Yes, we are just looking for one. What's the charge per day?
  #Person1#: It's $ 20. If you are staying for more than 3 days in the city, the charge is $ 16 per day.
  #Person2#: That's reasonable.