Without doing any calculation, find the numbers which are surely not perfect squares :

**(i)** 153

**(ii)** 257

**(iii)** 408

**(iv)** 441

We know that a number ending with 2, 3, 7 or 8 is never a perfect square.

Therefore,

**(i)** 153 is not a perfect square.

**(ii)** 257 is not a perfect square.

**(iii)** 408 is not a perfect square.

**(iv)** 441 may be a perfect square.

So, 153, 257 and 408 are surely not perfect squares.