19. If Bis the width of formation, d is the height of the embankment, side slope S: 1, for a highway with no transverse slope, the area of cross-section is
20. The ground surface slopes 1 in 50 along a proposed railway embankment 150 m in length. The height of the embankment at zero chainage is 0.5 m, the width is 11 m and side slopes 2:1. If the falling gradient of the embankment is 1 in 150, the quantity of the earthwork calculated by Prismoidal formula, is