Question

Which of the following is an irreducible form of 210?

• A. $2\times 105$
• B. $2\times 3\times 35$
• C. $2\times 3\times 5\times 7$
• D. $2\times 3\times 5\times 9$

Answer 1

The correct option is C $2\times 3\times 5\times 7$

210 can be written as,
$210=2\times 105$
$=2\times 3\times 35$
$=2\times 3\times 5\times 7$
Since the above expression can not be factorized further.
So, the irreducible form of 210 is
$2\times 3\times 5\times 7.$