Answer:
You have a total of 2.25 cups of liquid each time you add 2 cups of water with .25 cups of concentrate.
You want to know how many times 2.25 cup "units" there are in 18 cups.
(18)/(2.25) = 8, so you have 8 "units" of water and concentrate
In each of those 8 "units" you have .25 cups concentrate, so (8)(.25) = 2 cups of concentrate.
In each of the "units" you have 2 cups of water, so (8)(2) = 16 cups water.
Please let me know if you have any questions.
Step-by-step explanation: