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 $1.3m$, then the volume of water already used from the tank is $\frac{k}{2}{m}^3$. Find the value of $k$.

Answer 1

Volume of cube $=($ side ${)}^3=15.625m^3$
$\Rightarrow$ side $=2.5m$

Now, the depth of water is $1.3m$

Therefore, current volume $=$ Volume of cuboid $=lbh=2.5\left(2.5\right)1.3=8.125m^3$

Volume of water used $=15.625-8.125=7.5m^3$
$\frac{15}{2}{m}^3=\frac{k}{2}{m}^3$

Hence, $k=15$.