Tom is going to build a fence around his garden which is a rectangle measuring 8 m by 20 m. He will first put in posts which will be 4 m apart. If the posts cost $5.50 each, what will be the total cost for all the posts?

The first thing you should do for this case is to find the perimeter of the rectangle.

We have then:

P = 2L + 2W

Where,

L: long

W: wide.

Substituting the values:

P = 2 * (20) + 2 * (8)

P = 56 m

Then, to find the number of posts we have:

N = P / d

where,

P: perimeter

d: distance between posts.

Substituting:

N = (56) / (4) = 14

The total cost will be:

(5.50) * (14) = $ 77

Answer:

the total cost for all the posts wil be 77 $