Length of each side of the tank = 1.2 m
Volume of the tank = (1.2 m)3 m3 = 1.728 m3 = 1728 cu.dcm. = 1728 litre.
In 64 buckets water contained = (1-\frac{1}{3})=\frac{2}{3} part of the tank
=\frac{2}{3} × 1728 litre = 2 × 576 litre.
∴ 1 bucket contains =\frac{2 × 576}{64}= 18 litres