Final answer:
To find out how much margarine is needed for 15 people when a recipe requires 70 g for 5 people, we can use a ratio and proportion method leading to the solution of 1050 grams of margarine.
Step-by-step explanation:
The question involves a simple proportion to determine how much margarine is needed to scale up a recipe for 5 people using 70 g of margarine to a recipe for 15 people. If 70 g of margarine is required for 5 people, we can set up a ratio to find out the amount needed for 15 people. We can write this as 70 g margarine / 5 people = x g margarine / 15 people.
To solve for x (the amount of margarine for 15 people), we cross multiply and divide as follows:
5 people * x g margarine = 70 g margarine * 15 people
x = (70 g * 15) / 5
x = 1050 g
Therefore, 1050 grams of margarine is needed to make the same recipe for 15 people.