You have the following number
√27
In order to determine which letter best represent the previous number, you take into account the following square roots:
√25 = 5
√36 = 6
Then, you can consider that √27 is a number in between 5 and 6, because √27 in anumber in between √25 and √36.
The only letter that is in between 5 and 6 on the number line, is the letter C.
Hence, letter C best represents √27
