Question

The number which is not a perfect cube, from the following is:

• A. $1,331$
• B. $216$
• C. $243$
• D. $512$

Answer 1

The correct option is C $243$

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

Prime factorising, we get,

$1331=11\times 11\times 11={11}^3$, which is a perfect cube.

$216=2\times 2\times 2\times 3\times 3\times 3=2^3\times 3^3$, which is a perfect cube.
$243=3\times 3\times 3\times 3\times 3=3^3\times 3^2$, which is not a perfect cube.
$512=2\times 2\times 2\times 2\times 2\times 2\times 2\times 2\times 2=2^3\times 2^3\times 2^3$, which is a perfect cube.

Hence, option $C$ is correct.