MCQ
By what number should $81$ be divided to get a perfect cube?
  • A
    $6$
  • $3$
  • C
    $9$
  • D
    $7$

Answer

Correct option: B.
$3$
The prime factorisation of $81$ will be:
$81 = 3 \times 3 \times 3 \times 3$
$81 = 3^3 \times 3$
Hence, we need to divide $81$ by $3$ to get:
$\frac{81}{3}=27=3^3$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free