conversations.from: human
conversations.value: Of the 20 available cars for rent, 12 are automatic cars, 4 are manual cars, and the rest are semi-automatic. What percentage of the cars are semi-automatic?
  Give me a solution to this problem
conversations.from: assistant
conversations.value: 12 + 4 = 16 cars are either automatic or manual.
  So, 20 - 16 = 4 cars are semi-automatic.
  Therefore, the percentage of semi-automatic cars is 4/20 x 100% = 20%.