Selah and Mohammed want to prepare crêpes for all of the students in their French class. A recipe makes 20 crêpes with a certain amount of flour, milk, and 2 eggs. The girls already know that they have plenty of flour and milk to make 50 crêpes, but they need to determine the number of eggs they will need for the recipe because they are not sure they have enough. Considering the amount of eggs necessary to make the crêpes, what does the constant or proportionality mean in the context of this problem?