Shunned by a mp3 player that usually sells for $60 at a discount of 15%. how much was the discount? what did john pay for the discount mp3 player?

Ineed with number 17 i don’t get it at alll

5500 dollars is placed in an account with an annual interest rate of 6.5%. to the nearest tenth of a year, how long will it take for the account value to reach 19700 dollars?

Sara made $253 for 11 hours of work. at the same rate how much would he make for 7 hours of work?