Question

the rainfall on a certain day was 6 cm. how many litre of water fell on 3 hectares of field on that day?

Answer 1

Water level Reach (height)=6cm or 0.06 m
Covering Total Field(Area)=3 hectares

1 hectare=10000 m²
3 hectares=30000m²

Area=Length×Breadth
Area=30000m²

Since Field size will like Cuboid

Volume=Length×Breadth×Height

Length×Breadth=30000m²
Height=0.06 m

Volume=30000×0.06
$volume = 30000 \times \frac{6}{100} \\ = 1800 \: m {}^{3}$

As you Might Know
1m³=1000 litres
1800 m³=1800×1000
=1800000 litres

Total Water=1800000 litres