Question

Mr. Mosey wants to bake a cake for the teachers in his school. He found a recipe that calls for 3/4 cups of cocoa to make an 8 serving cake. However, he needs to make a cake that serves 4 times as many people. He also wants to add a little extra cocoa to make the cake taste better so he wants to add another 3/8 of a cup of cocoa. Write a number sentence to help him determine the amount of cocoa he needs and then solve to find the amount of cocoa needed.

Answer 1

Mr. Mosey needs 9/2 cups of cocoa to make a 32 serving cake.

Explanation:

For an 8 serving cake Mr. Mosey needs 3/4 cups of cocoa plus 3/8 cups of cocoa because he wants it to taste better. Then, for an 8 serving cake he needs:

Cocoa (8 serving cake)=3/4+3/8= 9/8 cups

But, he needs to make a cake that serves 4 times as many people, then he need a 32 serving cake (8*4=32). What we do is to multiply the above formula times 4:

Cocoa (32 serving cake)= 4(3/4+3/8)= 36/8 cups= 9/2 cups

He needs 9/2 cups of cocoa to make a 32 serving cake.