Question

Devon likes to take his car to his Rub-a-Dub Carwash because he is premier member there. His membership fee costs a $100 and that membership allows him to get his car washed for $12 every visit. Is this relationship proportional or non-proportional, why or why not?

Answer 1

Non-proportional.

Explanation:

Membership fee of Rub-a-Dub Carwash = $100

Cost of every car wash in his visit = $12

Total payment Devon has to make in x car washes = $(12x + 100)

Graph of the relation between "total payment" and "number of visits", doesn't pass through origin. (having y-intercept = 100)

While for proportional relationship graph should pass through origin.

Therefore, this relationship is non-proportional.