Question

A regular tank measuring 30 cm by 10 cm by 20 cm is 2/3 filled with water. Calculate the volume of water in the tank in litres. ( 1 litre = 1000 cm 3 )​

Answer 1

4 litres

Explanation:

First, find the volume of the entire tank using the given measurements:

`30 cm*10cm*20cm=6000cm^3`

To find the amount of water in cubic centimetres, simply multiply
`(2)/(3)` with 6000:

`(2)/(3) * 6000cm^3=4000cm^3`

Now, we need to convert to litres. You can easily see just by looking at the numbers that the volume is 4 litres, however we will do the full conversion just to show you how it's done:

`(1 Litre)/(1000cm^3) *(4000cm^3)/(1) \\`

Now, the cubic centimetres cancel out as there is one on the bottom of the first fraction and one on the top of the second fraction. Anything divided by itself is one, including units, so the 1000 cubic centimetres from the first fraction and the 4000 cubic centimetres from the second fraction are multiplied by one. They therefore remain the same but without the unit of centimetres cubed:

`(1 Litre)/(1000) *(4000)/(1)\\\\(4000 Litres)/(1000)\\\\4 Litres`