Question

A man has a garden 10 meters square to fence. How many fence posts are needed if each post is 1 meter from the adjacent posts?

Answer 1

39

Answer 2

If the garden is square and has sides of n metres, then each side will require 2+(n-1) posts with the 2 posts at the corners. As the corner posts are common with adjacent sides then the total number of posts is

4 sides of n-1 plus 4 corner posts.

4(n-1) + 4.

if n=10 then the number of posts is

4(10-1)+4=40