The perimeter of a rectangle is 30 inches. If its length is three times its width, find the dimensions. 30 inches=2(L+W) Divide each side by 2. 15 inches=L+W Substitute for L.
I take it you mean the average gallons lost an hour, in which case you would do 58,432.4 - 56,475.2 to get 1,597.2 to which you divide by 2 getting your final answer of 978.6