You can do this !
The rectangular prism has
-- length = 10 cm
-- width = 7 cm
-- height = 3 cm.
-- The area of the top and bottom is (length x width) each.
-- The area of the left and right sides is (length x height) each.
-- The area of the front and back is (width x height) each.
There. I just laid out all the schmartz you need to answer this question.
The rest is all simple arithmetic, and you're perfectly capable of turning
the crank and getting the answer. You don't need anybody else to do
that part for you.
Don't forget your units. The area of each flat face is (cm) times (cm),
and that product will be some cm² , for area.
welll...you have there written just one relationship...it is berween 280 and 4 hours...you have to figure out speed:

it is speed per hour
then you just connect time and speed:
- 140 - 2
- 280 - 4
- 350 - 5
- 420 - 6
- 560 - 8
- 700 - 10
35 divided by 573 is 0.0610820244328098
$58,685 would be the amount left over.