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?
(Hint: The digits 1, 0 and 8 stay the same when viewed upside down, whereas 9 becomes 6 and 6 becomes 9.)
Solution:
Three-digit perfect squares are 196 and 961, which looks same when viewed upside down.