Correct Answer - Option 1 : 100.405 m
Concept:
Reduced level (RL) of station A = RL of bench mark + BS reading – FS reading
Calculation:
Given:
Backsight (BS) reading on bench mark = 1.215 m
Reduced level (RL) of bench mark = 101.00 m
Foresight (FS) reading at a station = 1.810 m
Reduced level (RL) of station A = RL of bench mark + BS reading – FS reading
= 101 + 1.215 – 1.810
= 100.405 m