57) What is reduced level, if height of line of collimation is 98.717m and inter sight is 1.238m?

58) What is the difference in level if back sight reading 1.430m and inter sight reading 2.015m?

59) What is the height of Tee beam above the floor level if height of collimation of level on the floor 102.385m, inverted staff reading of the bottom of Tee beam - 3.890m and R.L of floor level 100.595m?

60) What is the difference in level if back sight of reading 3.370m inter sight of reading 2.975m?

61) What is the correction for curvature for a distance of 10km (Correction of curvature =0.0785D²)?