An Abs Diet Riddle by Michael Ma

3 friends who are all on the Abs Diet go on a Road Trip. They are lost and it becomes increasingly late at night. They're all out of power foods except a bag of 30 fresh organic fuji apples in the trunk (divided up, they have 10 apples for each of them). Its pitch black and they end up in Amish Country where they ask a family on a farm if they could sleep in the barn for the night. To thank the family for their generosity, the each of the 3 friends offer their 10 apples (30 total). Since apples are not in season, the family are delighted to accept. Later that evening the family realizes they don't want their guests to go hungry so they send their son with a bowl of 5 apples to the barn. On the way to the barn, the son decides to keep two of the apples since he figured it would be hard to divide 5 apples between 3 people. Each of the 3 friends get an apple back.

So to stay at the barn for the night, it cost each of the 3 friends 9 apples each (27 total). The son kept 2 apples. That makes 29 apples. What happened to that other apple?