Answer:
We can solve this problem by several ways, what we're going to do is calculating how much does a ounce cup cost, and, if we know that an 8-ounce cup costs 3.60 dollars, to know how much does one cost, we divide
3.60/8 = 0.450
Now, we know each ounce costs 4.50 and we can multiply the price by 20 to know how much will it cost:
0.450 * 20 = 9 dollars
You could also have done this problem by doing this:
8 ---- 3.60
20 --- x
And solve: x
= 9