Question

Which of the following cannot be a perfect square?

• A. $841$
• B. $529$
• C. $198$
• D. All of the above

Answer 1

The correct option is C

$198$

Explanation for the correct option:

Option (C): Determine the number which is not a perfect square.

A number with units $2,3,7,\mathrm{or}8$ should never be a perfect square.

Since the number $198$ has $8$ at the unit's place, $198$ cannot be a perfect square.

Hence, option (C) is correct.

Explanation for the incorrect options:

Option (A): The numbers $841$ have $1$at the unit's places, $841$ can be a perfect squares and $841={29}^2$.

So, option (A) is incorrect.

Option (B): The numbers $529$ have $9$ at the unit's places, $529$ can be a perfect square.and $529={23}^2$.

So, option (A) is incorrect.

Option (D): Since All the options are not the correct option.

So, Option (D) is incorrect

Therefore, options (A), (B), and (D) are incorrect.

Hence, option (C) is correct.