Which of the following is NOT a perfect square?
- 49
- 81
- 121
- 132
Show answer and solution
Correct answer: D. 132
49 = 7², 81 = 9², 121 = 11².
Now 11² = 121 and 12² = 144, so there is no natural number n with n² = 132. Therefore 132 is not a perfect square.