Dilution calculation (juice)

Suppose you have 2 L of orange drink containing 50% orange juice and 50% water (by volume). The drink was made from 1 L of orange juice and 1 L of water. You want to dilute this drink so that it contains only 20% orange juice. How much water should you add?

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A 20% orange juice-water mixture would contain 20 parts juice in 100 parts of mixture (by volume).

20/100 = 1/5

The above ratio shows that we would have 1 part juice to 5 parts total. The 2 liters of made up orange drink contains 1 liter of juice and one liter of water. If we added 3 more liters of water, we would have 1 liter juice in 5 liters total.

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