What was the question for this implicit rationale, and corresponding answer?
If the first car was made 10 years earlier than the second car, then the manufacture date for the second car is 1970 + 10 = 1980. The third car was manufactured 20 years after the second car was made, which is 1980 + 20 = 2000.
 The answer: 2000
The question: Three old cars displayed in an auction event have different manufacture dates. The first car, made in 1970, was made 10 years earlier than the second car. The third car was manufactured 20 years later after the second car was manufactured. Calculate the year that the third car was made.