Barbara mixes 54 ounces of granola and 36 ounces of raisins:
54 ounces + 36 ounces = 90 ounces
Now, if you would like to divide this mixture into 6 ounces servings, you can do it like this:
90 ounces / 6 ounces = 15 servings
Result: Barbara makes 15 servings.
