At the post office, Karen mails three packages that weigh 7.2, 7.5, and 7.9 pounds. The post office that Karen
uses rounds the weight of a package to the nearest pound to determine the price of shipment. It costs $3 to
mail a package that weighs 7 pounds and $3.75 for packages that weigh 8 pounds.
(a) How much did Karen pay to ship each package?
(b) Karen has $10.25 in her wallet in cash. Use subtraction to determine whether Karen has enough to
mail the three packages and how much extra money she has or needs.