A 100-m reach of sewer is to have a minimum capacity of 200 L/s. The street elevation at the upper manhole is 305.55 m and at the lower manhole is 303.05 m. Determine an appropriate pipe diameter and slope for this reach, and establish the pipe invert elevations at the upper and lower manholes. Assume that a minimum earth cover of 2 m above the pipe crown is required.