A fence enclosing a rectangular pen 100 feet long and 80 feet wide has a post at each corner and a post every 10 feet along the sides. How many posts does the fence have?

The total number of posts is 36.

Step-by-step explanation:

It is given that a fence enclosing a rectangular pen 100 feet long and 80 feet wide has a post at each corner and post every 10 feet along the sides.

Total number of posts on corners = 4

Because the distance between each post is 10 feet, so

Total number of posts along side measure 100 feet = 9

Total number of posts along side measure 80 feet = 7

Total number of posts is = 2 (9) + 2 (7) + 4 = 36

Therefore the total number of posts is 36.