One tractor can plow a field in 14 hours and another in 8 hours. Which tractor will plow more

One tractor can plow a field in 14 hours and another in 8 hours. Which tractor will plow more: the first one in seven hours or the second in five hours?

To solve the problem, you first need to determine the productivity of each of the tractors.
Suppose all work is 1.
In this case, the first tractor in 1 hour will do:
1/14 = 1/14 of the entire work.
We find the productivity of the second tractor in 1 hour.
1/8 = 1/8 of the entire work.
We find the amount of work done by the first tractor in 7 hours.
1/14 * 7 = 7/14 = 1/2 part of the entire work.
We find the amount of work done by the second tractor in 5 hours.
1/8 * 5 = 5/8 of the entire work.
1/2 <5/8.
Answer. A second tractor will do more work.