Question

A rectangular field is 80 m long and 60 m wide. If fence posts are placed at the corners and are 10 m apart along the 4 sides of the field, how many posts are needed to completely fence the field? 

(a) 24 

(b) 27 

(c) 28 

(d) 29

Answer 1

(c) 28

Let four posts be there at the corners A, B, C, D of the rectangular field.

Then, along the length AB, we have 7 posts and along the breadth BC, we have 5 posts.

∴ Total number of posts = 2 (7 + 5) + 4 = 28.