Answer:he will need to mix 20 cups of water if he uses 5 cups grape concentrate.
Explanation:
Henry mixes 1 cup grape concentrate with 4 cups water to make his favorite drink. It means that the number of cups of grape concentrate that henry requires to mix 1 cup of water would be
1/4
Therefore, the number of cups of water that he needs to mix if he uses 5 cups grape concentrate would be
5/(1/4) = 20 cups of water