Question

Robert can mow 3 1/2 acres in 3/4 of an hour on his riding lawn mower.

At this rate, how many hours will it take him to mow 8 acres?

Answer 1

It will take 1 5/7 hours

Explanation:

3/4 of an hour is;

3/4 * 60 minutes = 45 minutes

3 1/2 acres is done in 45 minutes

8 acres will be done in x minutes

Thus, mathematically;

3 1/2 * x = 8 * 45

7x/2 = 360

7x = 2 * 360

7x = 720

x = 720/7 minutes

Let us convert this to hours

That will be;

720/7/60 = 720/(60 * 7) = 720/420 = 12/7

= 1 5/7 hours