Prove that if a number is trebled then its cube is 27

Let us consider a number $n$. Then its cube would be $n^{3}$.

If the number $n$ is trebled, i.e., $3 n$, we get:

$(3 n)^{3}=3^{3} \times n^{3}=27 n^{3}$

It is evident that the cube of 3n is 27 times of the cube of n.

Hence, the statement is proved.