conversations.from: human
conversations.value: A mechanic charges $60 an hour to repair a car.  He works 8 hours a day for 14 days on one car.  The mechanic also used $2500 in parts.  How much did the car's owner have to pay?
conversations.from: assistant
conversations.value: The mechanic worked 8*14=112 hours
  So the labor cost 60*112=$6720
  That means the total cost was 6720+2500=$9220