Question

The smallest natural number by which $25$ must be multiplied to get a perfect cube is?

• A. $5$
• B. $20$
• C. $25$
• D. none of these

Answer 1

The correct option is A $5$

Prime factorising $25$, we get,

$25=5\times 5=5^2$.

We know, a perfect cube has multiples of $3$ as powers of prime factors.

Here, number of $5$'s is $2$.

So we need to multiply another $5$ in the factorization to make $25$ a perfect cube.

Hence, the smallest number by which $25$ must be multiplied to obtain a perfect cube is $5$.

Hence, option $A$ is correct.