Picking a month of the year and a day of the week

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?

Astore has clearance items that have been marked down by 60%. they are having a sale, advertising an additional 55% off clearance items. what percent of the original price do you end up paying?

If rs 900 amounts to rs 1044 in 4 years, what sum will amount to 1368 in 3 1/2 years at the same rate