Answer:
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Combine the two types of fruit drinks in the right proportions.
Let's use x pints for the 80% pure fruit juice and y pints for the 100% pure fruit juice.
We have two equations:
From equation 1, we can write
Now substitute this expression for y in equation 2:
Solve for x:
Now substitute x back into the expression for y:
The Royal Fruit Company must use 55 pints of the 80% and 165 pints of the 100% pure fruit juice drink.