Calculating Invert Levels

[@jseivwright_jm]

How do u calculate the invert level of a drain given just diameter, gradient,level of drain and height above cover.I wasn't taught this an I got it on a test

[@abhijeetsatyam7931]

chegg??

[@aamirabdulsalam]

you have reversed p with r

[@bonfacekavoi4320]

You working aren't visible try upgrade the camera