To determine the amount of flour needed for 15 people based on a recipe that serves 5 people, you can use a proportion to scale up the ingredients.
Let's set up the proportion:
5 people / 80 grams = 15 people / x grams
To solve for x (the amount of flour needed for 15 people), we can cross-multiply and then divide:
5 * x = 15 * 80
5x = 1200
x = 1200 / 5
x = 240
Therefore, you would need 240 grams of flour for a recipe that serves 15 people.