Q1) If 5 miles = 40 minutes.
Then, 5 * 3 = 15, and 40 * 3 = 120
In other words, it doesn't vary/differ because in order to get 15 miles in total you need one exact number, and since it's going by 5's and 40's you can just assume that 5 * 3 = 15 and 40 * 3 = 120 since 4 * 3 = 12.
Q2) Yes, of course the number of toppings varies because if you add more certain toppings it'd be added to your total, and customers can add more if they'd like. They don't need to do 4 specific toppings, it is up to them.