The answer for this question is 11 because the perfect square (which is no decimals just a whole number), so to get my answer for this, I basically divided whole number until I got my answer, 11*11 is 121. In other words, to get the answer for these question, it's always a whole number to the power of 2, here are some examples:
4=2
6=3
16=4
25=5
36=6
49=7
64=8
81=9
100=10
121=11
144=12
169=13
And so on
(Hint:the numbers on the left are square root numbers and the number to the right are the answers of the perfect squares. Ps. do you see pattern In the perfect squares, just follow that pattern and u will be successful, it's just +1 for the perfect squares so the nest perfect quart will be 14 and the square root will be 196)
I HOPE THIS HELPS ALOT