2.25¶

;  Give combinations of cars and cdrs that will pick 7 from each of the 
; following lists:
; (1 3 (5 7) 9)
; ((7))
; (1 (2 (3 (4 (5 (6 7))))))

; (i) (1 3 (5 7) 9)
(define a (list 1 3 (list 5 7) 9))
(car (cdr (car (cdr (cdr a))))) ;Value: 7

; (ii) ((7))
(define b (list (list 7)))
(car (car b)) ;Value: 7

; (iii) (1 (2 (3 (4 (5 (6 7))))))
(define c (list 1 (list 2 (list 3 (list 4 (list 5 (list 6 7)))))))
(car (cdr (car (cdr (car (cdr (car (cdr (car (cdr (car (cdr c)))))))))))) ;Value: 7