Given N, what is mABC?

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?

Iwill mark ad braniless pls just evens

Find two numbers if their ratio is 4: 7 and their difference is 123.