2 3 4 cups of oatmeal and makes one dozen muffins. If he makes 3 dozen muffins for a club meeting and 2 1 2 dozen muffins for a family reunion, how much oatmeal will he use?

15 1/8 cups of oatmeal will be used

Step-by-step explanation:

Firstly, we shall be calculating the total number of dozens of muffin made

That would be the addition of the dozens of muffin made for the family reunion and that made for the club meeting = 3 + 2 1/2 = 5 1/2 or simply 5.5 dozens

Now, from the question initially, 2 3/4 or simply 2.75 cups of oatmeal makes 1 dozen muffins

x cups of oatmeal = 5.5 dozens of muffin

x * 1 = 2.75 * 5.5

x = 15.125 cups of oatmeal or simply 15 1/8 cups of oatmeal