



 
Hi John, There are 277.419547 cubic inches. The volume of a cylinder is π r^{2} h where r is the radius, h is the height and π is approximately 3.1416. If the inside diameter of the pipe is 1 inch then for 30 gallons you have
or
which is 883 feet. Penny  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 