#| BEGIN (Write your solution here) |#
(define (cont-frac n d k)
  (define (iter i n d k)
    (if (= i k)
        (/ (n i) (d i))
        (/ (n i) (+ (d i) (iter (+ i 1) n d k)))))
  (iter 1 n d k))
#| END |#