I'm not sure how to do these
1.) Mr. Robins earns a commission on each airfare he books. At the end of the day, he had booked $208.60 worth of airfare and earned $31.29. What is the Mr Robins' commission rate?

2.) The bill at a restaurant came to $136.40. The patrons decided to leave a 15% rip. What was the total of the bill including tip?

3.) Winter coats are marked 70% oof on February 1st. If a coat costs $57.75 on January 31st, how much will it cost on February 1st?