James wants to build a wooden planter box for his garden with a volume of 100 cubic feet. If he constructed the planter with a height of 2 feet and a width of 5 feet, what should the length of the planter be, in feet?
You have to work backwards to find volume, so just divide the volume (100) by the height (2) then divide that by the width (5) and you get your answer, 10