First, you need the perimeter:
4 equal sections means
(3/2) = 4x where x is the length of one section
Find x:
(3/2) / 4=x
Simplify:
3/8 = x
Now that you know one section of the fence, you need to multiply that by 1/3
(3/8) * (1/3) = 1/8
So now you know 1/8 feet is painted on that one section of the fence
Then consider it being a part of the WHOLE fence:
3/2 * 1/8 = 3/16
So 3/16 of the whole fence was painted!
Hope this helps