How do you solve this with the fractions?

1foot = 12 inches; 1 yard = 3 feet

Liz is shipping a package to her friend.the maximum weight of a medium flat-rate box is 20 pounds,including the box which weighs 6 ounces.write and solve an inequality to describe the possible weight ,w, of the contents that liz will ship to her friend if she must use a medium flat-rate box.

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?