Question

In the following numbers, identify the perfect cube: $8,81,25,100$.

• A. $8$
• B. $81$
• C. $25$
• D. $100$

Answer 1

The correct option is A $8$

Here, prime factorization of:

$8=2\times 2\times 2=2^3$

$81=2\times 2\times 2\times 2=2^4$

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

$100=2\times 2\times 5\times 5=5^2\times 2^2$

A perfect cube has multiples of $3$ as powers of prime factors.

Here, only $8$ has powers of prime factors as the multiples of $3$.

Hence, option $A$ is correct.