UPSC NDA II 2014 Mathematics Paper

Distance between point of observation and foot of lamp = 150m
Angle of elevation of top of lamp = 30°
∘ Height of lamp h=AB
Now from fig ABC
the triangle ABC is a right angle triangle
‌ Hence, ‌tan‌C=‌

AB

BC

AB=150‌

1

√3

‌ Multiply and divided by ‌√3
‌‌=‌

150√3

√3×√3

‌‌=‌

150√3

3

‌‌=50√3m
‌ the height of the lamp post ‌=50√3m