Question

A three digit perfect square is such that if it is viewed upside down, the number seen is also a perfect square. What is the number $?$

Answer 1

Finding the number:

The digits$1,0,8$, stay the same when viewed upside down, where as $9$ becomes $6$ and $6$ becomes $9$

Let us consider number $169$

So, $169$ is a perfect square

Square root of $169=13$

That is $\sqrt{169}=13$

When we consider this number viewed upside down

So, we will see it as $961$

$\sqrt{961}=31$

Therefore $961$ is also a perfect square

Hence, $169$ is three digit perfect square number , such that if it is viewed upside down the number seen is also a perfect square .