Which graph represents a function?

Josh has a rewards card for a movie theater he receives 15 points for becoming a rewards card holder he earns 3.5 points for each visit to the movie theater he needs at least 55 points to earn a free movie ticket which inequality can josh use to determine x, the minimum number of visits he needs to earn his first free movie ticket.

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?

What function has a range {yly< 5}? question on picture above^