To come up with my answer, I determined the volume of the pipe in inches cubed, multiplied times the diameter. 125ft. (1500in.) x 28.27 (A = pi x r * r)Area of the assumed base of the pipe) = 42,405in cubed. Then, using a conversion calculator you would find that the volume in gallons would be 183.571 Gal. (US Liq). If we then divide this figure by 125, we would get the number of gallons per foot, which is 1.469. Sound right? : D
