Stadia readings were taken with a theodolite on a vertical staff with the telescope inclined at an angle of depression of 3º30′. The staff readings were 2.990, 2.055 and 1.120. The reduced level of the staff station is 100.000m, and the height of the instrument is 1.40 m. What is the reduced level of the ground at the instrument? Take constants as 100 and zero.