Final answer:
If the original recipe requires 2 cups of flour to serve 4 people, and 5 times more people are expected, then 10 cups of flour will be needed to serve 20 people.
Step-by-step explanation:
The question concerns the adjustment of ingredients in a recipe based on the number of servings required. Specifically, it relates to how many cups of flour are needed for a casserole when the number of people being served increases by five times. The original recipe calls for 2 cups of flour to serve 4 people. If five times more people are expected, this means there will be a total of 4 * 5, which equals 20 people coming for the meal.
To maintain the same flour to people ratio, you must multiply the original amount of flour by five. Therefore, you will simply calculate 2 cups of flour (for the original 4 people) times 5 (as five times more people are coming), which equals 10 cups of flour needed for 20 people.