An oatmeal recipe calls for 1 1/2 cups of oat and 2 1/2 cups of water. a if you have 3 cups of oats, how many cups of oats water do you need? 3 cups oat •= cups water. b if you have 2 cups of oats, how many cups of oats water do you need? 2 cups oat •= cups water. c if you have 5 cups of water, how many cups of oats do you need? 5 cups water • = of oat. d if you have 3 cups of water, how many cups of oats do you need? 3 cups water •= of oat.