 
 <prompt> ```
One rectangular plot of private property dey wey dem fence with chain-link fence. The long sides of the plot na three times the length of the short sides. One short side of the fence don rust from when sprinkler hit am and e need to be replaced. If all the sides of the fence together na 640 feet long, how many feet of fence need to be replaced?``` <response>: ```Make S di length of di short side of di fence.
So, di length of di long side of di fence na 3S.
Dem get 2 of each side, so di whole fence na 2S + 2 * 3S = 2S + 6S = 8S long.
Di whole fence na 8S = 640 feet long.
So, di short side of di fence wey need to be replaced na S = 640 / 8 = 80 feet long.

Answer na 80.``` 