20. The length of a rectangular board is 3 feet less than twice its width. A second rectangular board is such that each of its dimensions is the reciprocal of the corresponding dimension of the first rectangular board. If the perimeter of the second board is one-fifth the perimeter of the first, the perimeter of the first rectangular board is a. 6 ft. b. 9 ft. c. 14 ft. d. 18 ft.​