Find the volume and show work pls

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.

Im literally having a mental breakdown

Which equation represents a direct linear variationa. y=x2b. y=2/5xc. y=1/xd. y=x+3