Answer:
1.
3.5 days
2.
6.75 minutes, 6 minutes 45 seconds, 6.8 minutes to 1 dp
Step-by-step explanation:
1.
With double the amount of tractors it will take half the time.
7 divided by 2 is 3.5
2.
This is an example of inverse proportion. The job that has to be done to to prepare the vegetables, That stays the same.
However, the more people there are to do the work, the quicker it will get done.
There is a constant to be found:
x multiplied by y equals k
3 x 45 = 135
For 20 people:
20 x y = 135
135 divided by 20 is:
6.75, or 6.8