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2-digit Square

A 2-Digit number is squared. When this 2-digit number is reversed and squared, the difference between the squares is also a square. What is the 2-digit number?

Algebraic Average

Stage: 4 Short Challenge Level: Challenge Level:1
The sum of the three numbers is 3x, so y + z = 2x. Hence the mean of y and z is x.

Note: If the mean is taken out of a data set, the mean is left unchanged!

This problem is taken from the UKMT Mathematical Challenges.