The building sanitary drainage system is being installed. The line is a 4″ sanitary drain line that has an invert elevation of 8″ below thr finished floorelevation, at the start of the run. the pipe line runs 20` and makes a 90 d egree turn and runs another 80` before exiting the building. If the pipe is sloped at 1/4″ per foot, what is the invert elevation where it extis the building?

The building sanitary drainage system is being installed. The line is a 4″ sanitary drain line that has an invert elevation of 8″ below thr finished floorelevation, at the start of the run. the pipe line runs 20` and makes a 90 d egree turn and runs another 80` before exiting the building. If the pipe is sloped at 1/4″ per foot, what is the invert elevation where it extis the building?