A farmer wants to make a fence that is 32 ft. By 40 ft. If he wants to put up a fence post every 4 feet how many posts will he need?

I got 18 because 40 divided by 4 is 10 and 32 divided by 4 is 8 then I added 10 and 8 and got the answer of 18

Assuming a rectangular field,

total fence: 32+40+32+40 = 144 ft
144/4 = 36