conversations.from: human
conversations.value: Cid owns a mechanic shop, he charges $20 for an oil change, $30 for a repair, and $5 for a car wash. How much money did he earn if he changed the oil of 5 cars, repaired 10 cars, and washed 15 cars?
  Give me a solution to this problem
conversations.from: assistant
conversations.value: The money he earned from an oil change is $20 x 5 =$ 100.
  The money he earned from the repair is $30 x 10 = $300.
  The money he earned from the car wash is $15 x 5 = $75.
  Therefore, Cid earned a total of $100 + $300 + $75 = $475.