A cubical container with a side of 5 cm is filled with water up to a height of 2 cm.
extra water should be added to fill the container.

The correct option is C $75c{m}^3$

Given,
Side of cubical container ($l=b=h$) $=5cm$

Area of the base ($A$) $=l\times b=5\times 5=25c{m}^2$

Volume of the container = $A\times h=25\times 5=125c{m}^3$

Water is filled up to a height of 2 cm.

So, volume of the filled portion $=(A\times h)=25\times 2=50c{m}^3$

Amount of water to be added = Volume of the container - Volume of the filled portion

$=125c{m}^3-50c{m}^3=75c{m}^3$

Thus, the amount of water to be added to completely fill the container is $75c{m}^3$.