The answer is C.
(Optional) First, reorder the terms of this inequality so you know what you're working with. (x + 24 ≥ 55)
Subtract 24 on both sides of the ≥ sign.
x ≥ 31
When using either ≤ or ≥, it will be a closed circle on a number line. The direction of the sign acts as an arrow that tells you which direction the line will be going.
