Question

what will be the possible units digit for the square number 2 or 8 or 7 or 9​

Answer 1

The unit digit of a perfect square can be only 0, 1, 4, 5, 6 or 9. The square of a number having: 1 or 9 at the units place ends in1. 2 or 8 at the unitsplace ends in 4. 3 or 7 at the units place ends in 9.