Help me on this pls!!

Convert 16 yards to feet use the conversion rate 3 feet = 1 yard

Sara needs to take a taxi to get to the movies the taxi charges $4.00 for the first mile and then $2.75 for each mile after that if the total charge is $20.50 then how far was sara’s taxi ride to the movie

Use sigma notation to represent the following series for 9 terms.