Question

Question 2 (viii)
The following number is obviously not a perfect square. Give reasons.

505050

Answer 1

The square of any number generally has one of these digits 0, 1, 4, 5, 6 or 9 at its unit place.
Also, a number which is a perfect square may have even number of zeroes at its end.

505050 has one zero at the end of it. However, a perfect square cannot end with an odd number of zeroes, it is not a perfect square.