16 1/2 cup servings if they are putting the grape juice and the lemonade together then that adds up to be 8 and then you have to fine how many 1/2 cups you can get out of 8 which is going to be twice as much so it's 16
With Sine, Cosine, and Tangent there are no limits with the numbers you can use and they can be found on a calculator. When you press one of the 3 it will show up like:
