Question

Which of the following is a perfect square as well as a cube

• A. $64$
• B. $125$
• C. $81$
• D. $343$

Answer 1

The correct option is A

$64$

Explanation for all correct answers:

Option A: $64$

The number $64$ is equal to $2\times 2\times 2\times 2\times 2\times 2$.

So, $64$ is equal to a cube of $2\times 2=4$ and a square of $2\times 2\times 2=8$.

So, the option (A): $64$ is a perfect square and a perfect cube.

Explanation for all incorrect answers:

Option B: $125$

The number $125$ is equal to $5\times 5\times 5$.

So, the number in option (B): $125$ is a cube of $5$ but not a complete square of any number.

Option C: $81$

The number $81$ is equal to $3\times 3\times 3\times 3$.

So, the number in option (C): $81$ is a square of $3\times 3=9$ but not a cube.

Option D: $343$

The number $343$ is equal to $7\times 7\times 7$.

So, the number in option (D): $343$ is a cube of $7$ but not a complete square of any number.

Hence, the correct option is (A).