Answer:
4 cups of lemon juice
Explanation:
1. There are 16 cups in one gallon. Therefore, if Dwayne uses 1 gallon of water, he is using 16 cups.
2. The recipe states that for every 6 cups of water used, 1 1/2 cups of lemon juice should be used. Knowing this, we can come up with a conversion factor that is written in fraction form.
3. Because we have a conversion factor, we can multiply this by the 16 cups of water that Dwayne is using to calculate how much lemon juice he needs.
(water unit cancels out)