Question

A storage tank is in the form of a cube. When it is full of water, the volume of water is $15.625m^3$. If the present depth of water is 1.3 m, then find the volume of water already used from the tank.

Answer 1

Let the side of cube $=xm$
Volume of cubical tank $=15.625m^3$ [given]
$\Rightarrow x^3=15.625m^3$
$\Rightarrow x=2.5m$
And present depth of the water in the cubical tank = 1.3 m
$\therefore$ Height of water used = 2.5 - 1.3 = 1.2 m
Now, volume of water used $=1.2\times 2.5\times 2.5=7.5m^3$ [volume of cubical tank$=l\times b\times h$]
$=7.5\times 1000=7500L$ $[\because 1m^3=1000L]$
Hence, the volume of water already used from the tanks is 7500 L.