What present of 65 is 13

Dylan and dusty plan to take weekly surfing lessons together. if the 2-hour lessons are $20 per person and they plan to spend $100 each on new surfboards, what is the maximum number of lessons the two can take if the total amount spent for lessons and surfboards is at most $480?

How can you tell when x and y are not directly proportional?

Solve this problem! extra ! 3025/5.5 = a/90.75 / = fraction