answer: #Person2# helps #Person1# to book an air ticket and gives #Person1# ten percent off.
documents: #Person1#: Excuse me. Can I get a ticket on the next flight to Frankfurt?
  #Person2#: Sure. It will depart 2 hours later.
  #Person1#: What's the fare for a single ticket?
  #Person2#: That's $ 150.
  #Person1#: Can you give me a special offer?
  #Person2#: Of course. Right now it is the slack season, we will give you ten percent off.
  #Person1#: How about a round trip? Could you offer us something more?
  #Person2#: I am sorry, there is no difference.