Which set of ordered pairs (x,y,) could represent a linear function of x?

In fractions and ratios, they're typically simplified. For example, 6:4 can be simplified down to 3:2. A simplified ratio like 4:3 could be changed into 8:6.

Knowing this, we technically have two ratios in this question: 5:2 and 20:w (whereas 'w' represents the unknown number of wrong answers)

Can you sort of guess where this is going? We have to "unsimplify" the 5:2 ratio in order to find what 'w' is.

In order to turn 5 into 20, we simply have to multiply both sides by 4.
5:2 = 20:8

Looks like we've found our answer.
Billy answered 20 questions right and 8 questions wrong.

There were 28 questions on the quiz.

If you need me to explain anything I did here, just let me know :)
-T.B.