Question

it was told that numbers ending with digits 1,4,5,6,9 are perfect squares then howcome 156 is not a perfect square??

Answer 1

All the perfect squares end with one of the digits of 1,4,5,6,9.
But all the numbers ending with these digits cannot be perfect squares.
So the converse of the statement "All the perfect squares end with one of the digits of 1,4,5,6,9" need not be true.