conversations.from: human
conversations.value: John sends his son to prep school.  It cost $20,000 per semester.  There are 2 semesters in the year.  How much does it cost to send the kid to 13 years of school?
  Give me a solution to this problem
conversations.from: assistant
conversations.value: It cost 20000*2=$40,000 a year
  So it cost 40,000*13=$520,000