Question

16* is perfect square. What the number in place of the asterisk ?

Answer 1

the asterisk can be
1 power 2=1
2 power 2=4
3 power 2=9
but don't go to 4 power 2 it becomes 16 2 digits number
so asterisk can be replaced with 1/4/9
as given it is a perfect square so the number will be 169 that is square of 13

Answer 2

In place of * there will be 9. so that 169 is perfect square of 13.