Answer:
2/3 parts of water
Step-by-step explanation:
For solving the question it is necessary to use the rule of three, in which we know that 2 parts of water are mixed with 3 parts of juice, then, how many parts of water are mixed with 1 part of fruit juice. That can be written as:
2 parts of water ------------------ 3 parts of Fruit Juice
X ------------------ 1 part of Fruit Juice
Where X is the parts of water that are mixed with 1 part of fruit juice. Solving for X we get:

X=
parts of water
Finally, for made the beverage, 1 part of fruit juice is mixed with
parts of water.