Not all numbers that end in 0,1,4,5,6 are a perfect square.
Find numbers from 100 to 400 that end with 0, 1, 4, 5, 6 or 9, which are perfect squares.
Write all numbers from 400 to 425 which end in 2, 3, 7 or 8. Check if any of these is a perfect square.
Out of all the two digit numbers, what is the probability of the number not being a perfect square?