Which of the following can't be the unit's digit of a perfect square?
8
The units digit of \(n^2\) depends only on the units digit of \(n\). Squaring 0-9 gives units digits \(\{0,1,4,9,6,5,6,9,4,1\}\), so a perfect square can end only in 0, 1, 4, 5, 6 or 9.
Digits 2, 3, 7 and 8 never appear. Among the given options, 8 is the impossible units digit.
What is the square root of 123454321?
With what number should you multiply 117 to make it a perfect square.
The square root of 2025 is
Which of the following numbers is not a perfect square?