Alright, so for question C, you eat 9 cups of dairy delight yogurt (which i will call ddy) how many grams of fat did you eat? So on the label for ddy, is says 5 grams in 11 cups, but you want to know how many grams in 9 cups. So, divide 5 by 11. That gives you grams per cup. Multiply that answer by 9, and that is how many grams of fat is in 9 cups of ddy. Round to the nearest thousandth.
For question D, its somewhat the same process. You eat 5 cups of Farm Maid Yogurt (fmy) and 3 cups of ddy. How many grams per cup. So take 5 and divide it by 11. And take 6 and divide it by 13. Now you have grams per cup for ddy and fmy. Multiply you answer for ddy and multiply it by 3 and take your answer for fmy and multiply it by 5. Add both answers together and that's your answer.