Question

A cubical tank has a volume of 8000 $m^3$. What is the height of the tank?

• A. 2000cm
• B. 2400cm
• C. 2800cm
• D. 2700cm

Answer 1

The correct option is A 2000cm

Volume of cube = $a^3$, where a is the side length of the cube.

In any cube, length, breadth and height are all equal. So, the dimension of the cubical tank can be found by finding the cube root of 8000.
$\begin{array}{cc}2& 8000\\ 2& 4000\\ 2& 2000\\ 2& 1000\\ 2& 500\\ 2& 250\\ 5& 125\\ 5& 25\\ 5& 5\\ & 1\end{array}$

Prime factorisation of 8000 = 2 $\times$ 2 $\times$ 2 $\times$ 2 $\times$ 2 $\times$ 2 $\times$5 $\times$ 5 $\times$ 5

$\sqrt[3]{38000m^3}$ = $\sqrt[3]{3(2^3\times 2^3\times 5^3)m^3}$
$=2\times 2\times 5=20m$

Hence, height of tank = 20 $\times$ 100 = 2000cm