can anyone tell me why it evaluates to 240! the language is scheme R5h5. Thanks

(c) (2 points.) To what does the following expression evaluate? (let ((x 10) (y 20) (z 40)) (let ((x (+ y 1)) (y (+ x 2)) (z (lambda (z) (* z y)))) (z y))) It would evaluate to 240. (c) (2 points.) To what does the following expression evaluate? (let ((x 10) (y 20) (z 40)) (let ((x (+ y 1)) (y (+ x 2)) (z (lambda (z) (* z y)))) (z y))) It would evaluate to 240