6tractors take 6 days to collect the harvest how long would it take 9 tractors to do the same work

If 6 tractors equals 6 days, than 9 tractors will only take 3 days because you have more tractors to do the same amount of work but since you have more help with tractors the less it will take you to harvest. Most people assume 9 days since they aren't thinking but they just need to actually read properly the question.

I would say 9 hours because if it took 6 tractors 6 days to harvest