Let statement is not ok within the beginning student mode, maybe change to condition please

The code I have now is not ok to run:

(define (photo-mugs mugs previous-orders) (let ((discount (if (> previous-orders 3) 11.50 0)) (setup (if (= mugs 65) (quotient mugs 5) 0))) (+ (* (- mugs free-mugs) (- base-price discount)) setup))) photo-mugs 1 1

Please change this code by replacing the let statement for me thanks a lot!

Question 3: Ordering customized photo mugs ABC Photo Centre sells custom printed photo mugs. Like many places, the price per unit decreases with large orders. In addition, they like to reward loyal customers (those who have more than 3 previous orders with them) by providing further discounts on large orders. Details, including charges for initial set-up, are provided in the table below. Write a function photo-mugs that consumes a positive integer for the number of photo mugs being ordered, a natural number for number of previous orders, and produces the total cost of the order for the mugs. Do not round the finol onswer in any way. For example, Save your code in a file called a02u3. rkt and submit it to MarkUs