Question

The units digit of a perfect square is 6. What are the possible values of the tens digit?

Answer 1

As we know only square of 4 and 6  having 6 as unit digit. All the other digit doesn't have 6 in unit digit of two digit number.

Square of 4 is = $(4)^2 = 16$

Square of 6 is = $(6)^2 = 36$

So the possible value for tenth digit is 1 and 3.