;; tax : number -> number
;; Example (tax 100) -> 52.5
(define (tax grosspay)
  (* (/ 15.0 100) grosspay))

;; grosspay : number -> number
;; Example (grosspay 100) -> 1200
(define (grosspay h)
  (* h 12))

;; netpay : number -> number
;; Example (netpay 100) -> 1020
(define (netpay h)
  (- (grosspay h) (tax (grosspay h))))