Need help with this ASAP it’s dividing rational expressions

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?

To decrease an amount by 16% what single multiplier would you use

What’s the range cuz i can’t find it?