Answer:
If a reduced fat cookie contains 8 g of fat per serving, and in order for food to be termed "reduced fat", it must have at least 20% less fat than the regular item, then we can conclude that a serving of the regular cookie has at least 10 g of fat.
Here's the math: Let's say that `x` is the amount of fat in a serving of the regular cookie. If the reduced fat cookie has 20% less fat, then it has `0.8 * x` grams of fat per serving. Since we know that the reduced fat cookie has 8 g of fat per serving, we can set up the equation `0.8 * x = 8`. Solving for `x`, we get `x = 10`. So, a serving of the regular cookie has at least 10 g of fat.