Question

A cake recipe requires 3 1/4 cups of flour for 13 servings and 4 1/2 cups of flour for 18 servings. How much flour is required to make a cake that serves 28?

Answer 1

10 cups because 3 1/4 and 4 1/2 is 7/4 and 18/4 respectively. Then, you subtract them and add the answer to 18/4 twice.