Actually, I wrote the unit as litres because you're measuring the volume of **water**.

Base Area x Height = Volume

100 x 12 = 1200 L

And to find out 1/3 of it, times the total volume by 1/3 or devide the total volume by 3.

1200/3 = 400 L

1200 x 1/3 = 400 L

]]>V = 100× 12 = 1200

If the cylinder is 1/3 full then the water volume is 1/3 the volume of the cylinder;

1200/3 = 400 m^3

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