Question

Which of the following sets would have a graph with an open circle on 5 and a ray pointing right on the number line?

Answer 1

Answer: Choice C  $\{x | x \in \mathbb{R}, \ x > 5 \}$

The open circle means we do not include the endpoint, hence the use of a greater than symbol. If we were to include the endpoint, then we'd have greater than or equal to. We can rule out choice B due to this reasoning.

The ray pointing to the right indicates we are talking about x values larger than 5, so we can rule out choice A and conclude the answer is C.

Side note: The notation $x \in \mathbb{R}$ is saying "x is a real number"