There is a slight mistake in the question...the side cannot be 36cm^2
assuming that the area of the side of cube=36sqcm=a^2
(a is the length of the side)
a =sqrt36=6
Litres of water that will contain=length *breadth*height
=a*a*a
=6*6*6
=216cm^3
=216*10^-3 cm^3