Question 16
a) Find the smallest square with last digit not $0$ which becomes another square (not zero) by the deletion of its last two digits.
b) Find all squares, not containing the digits $0$ or $5$, such that if the second digit is deleted the resulting number divides the original one.
b) Find all squares, not containing the digits $0$ or $5$, such that if the second digit is deleted the resulting number divides the original one.