The total length of the fence in feet = 400 feet
Posts are required at a distance of 8 feet
Total number of posts required = 400/8 = 50 posts
The 50 posts will include the post at the end since the last post will be placed at the 400 feet position which would mark the end of the fence.
Additionally, one more post will be required at the beginning since the first post will be placed at 8 feet from the start.
So total number of posts = 50 + 1 = 51 posts
Total number of posts required for the fence if it begins and ends with a post = 51 posts