#lang racket

(define T '(1 3 5 7 9))

; Eg 1 - use map operator on your own add 1 function

(map (lambda(x) (+ 1 x)) T)

; or even better, use the built in function
(map add1 T)


; Eg 2 - use the fold operator

(foldl (lambda (x r) (+ x r)) 0 T)

; or even better for most algebraic style operations that take arbitrary 
; numbers of parameters, apply will pass the whole list and the operator
; will do the folding.

(apply + T)