You have 3/5 cup of oatmeal in your cupboard. A recipe for cookies calls for 1/4 cup of oatmeal. How much oatmeal would you have left if you made the cookies?

The recipe calls for 4/3 cups of oatmeal and 9/2 cups of flour.

If we convert them to a common denominator, we have 8/6 cups of oatmeal and 27/6 cups of flour, so, the ratio is 8:27.

If you use 6 cups of oatmeal and 9 cups of flour, the ratio will become 2:3 and will no longer be proportional