UPSC CDS 1 2022 Math Paper

Given:
Height of rain water =5cm
Area of ground =2 hectares =2×108cm2
Concept used:
Volume = Area of base × Height
1 hectare =100000000cm2 or 108cm2
1cm=1∕100m or 1∕102m
lculation:
Volume of water that falls on the ground =2×108×5
⇒10×108cm3
⇒109cm3
Now we need to convert it into m3
⇒109×(1∕10)6m3‌‌[∵{(1∕10)2}3=(1∕10)6]
⇒103m3
⇒1000 cubic meter
∴ The volume of water that falls on 2 hectares of ground is 1000 cubic meters.