200
Troy is helping his father build a fence. Each section of the fence has a post at each end. Make a table showing how many posts will be needed it there are 1, 3, 5, 10, 15, or 20 sections of the fence.
Sections: 1, 3, 5, 10, 15 20. Posts: 2, 4, 6, 11, 16, 21