Answer in complete sentences.

Q1: A marathoner ran 5 miles in 40 minutes and 15 miles in 120 minutes. Does the number of minutes vary directly with the number of miles?

Q2: A large pizza with one topping costs $15.50. A large pizza with four toppings costs $20. Does the price vary with the number of toppings?

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.