Answer:
82 ft.
Explanation:
First things first you need the least common denominator which would be 40. Whatever is done to the bottom is done to the top so we have our new fractions 42 25/40 and 39 15/40. 39 + 42 = 81, 25 + 15 = 40, so it’s 81 40/40 which = 82 because any number over itself is 1.
Hope this helped!