A recipe calls for 1 cup of cake mix and four eggs the recipe serves 6 people. How many eggs are needed enough to serve 15 people?

Well you have to keep in mind that if you increase the egg amount, you also have to increase the cake mix amount as well. Baking requires precise measurement unfortunately.

So 1st thing you would have to do is double your recipe so that it serves 12 people. That would make it 2cups of cake mix and 8 eggs.

But you want to make 15 which means you need half of the recipe so that it serves 3 and not 6. That would make you double batch of 12 to 15 servings.

So you would need another 1/2 cup of cake mix and 2 more eggs, so your total would be:

2 &1/2 cup cake mix and 10 eggs.....remember you can't increase one and not the other. That won't work in baking.