Question

In which of the following prime factorization has not been done. (1)$54=2\times 3\times 9$ (2) $70=2\times 5\times 7$ (3) $24=2\times 3\times 4$ (4)$56=7\times 2\times 2\times 2$

• A. Both 1 and 2
• B. Both 3 and 4
• C. Both 1 and 3
• D. None of these.

Answer 1

The correct option is C

Both 1 and 3

Factorizing each number to find its prime factors

The prime factorization of $54$ is $2\times 3\times 3\times 3$.

The prime factorization of $70$ is $2\times 5\times 7$.

The prime factorization of $24$ is $2\times 2\times 2\times 3$.

The prime factorization of $56$ is $2\times 2\times 2\times 7$.

we can see that both $\left(1\right)$ and $\left(3\right)$ have not been factorized properly.

Therefore, In $\left(1\right)$ and $\left(3\right)$ prime factorization has not been done.

Hence option (C) is the correct answer.