Ingredients for a pizza cost $3. What happens to that variable cost as the number of pizzas sold rises from 200 to 800?

1. A variable cost is incurred once for every unit sold, so the per unit amount does not move with volume. 2. At 200 pizzas the total variable cost is 200 times $3, which is $600. 3. At 800 pizzas the total variable cost is 800 times $3, which is $2,400. 4. The rate stays at $3 while the total rises, which is the defining behaviour of a variable cost. _Source: Jonick, Principles of Managerial Accounting (UNG Press, CC BY-SA 4.0), section 5.1 Introduction_