Question
Which of the following are perfect cube$?$
$3087$
$3087$
✓
Answer
On factorising $3087$ into prime factors, we get 3087 $= 3 \times 3 \times 7 \times 7 \times 7$ Group the factors in triples of equal factors as: $3087 = 3 \times 3 \times \{7 \times 7 \times 7\}$ It is evident that the prime factors of $3087$ can be grouped into triples of equal factors and no factor is left over. Therefore, $243$ is a perfect cube.
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