<Li> if the last digit of a number is 3 or 7, its square ends in 9; </Li> <Li> if the last digit of a number is 4 or 6, its square ends in 6; and </Li> <Li> if the last digit of a number is 5, its square ends in 5 (in fact, the last two digits must be 25). </Li> <P> In base 12, a square number can end only with square digits (like in base 12, a prime number can end only with prime digits or 1), i.e. 0, 1, 4 or 9, as follows: </P>

Which of the following is not equal to the square of an integer