A solution is made by mixing 20% alcohol with 80% water. If 15 liters of alcohol are used, how many liters of the solution are there in total? - Parker Core Knowledge

Understanding the Context

A solution described as “20% alcohol” means that for every 100 liters of the mixture, 20 liters are alcohol and 80 liters are water. This ratio applies proportionally regardless of the total volume.

Let’s define:

• The volume of alcohol = 20% of the total solution
  
• The known quantity of alcohol = 15 liters

Let the total volume of the solution be x liters. Then,
20% of x = 15 liters
or
0.20 × x = 15

Solving for Total Volume

Key Insights

To find x, divide both sides by 0.20:
x = 15 ÷ 0.20
x = 75

Thus, the total volume of the solution is 75 liters.

Verifying the Water Content

To ensure accuracy, let’s verify:

• 20% of 75 liters = 0.20 × 75 = 15 liters alcohol ✔
  
• 80% of 75 liters = 0.80 × 75 = 60 liters water ✔

The values align perfectly with the stated composition.

Final Thoughts

Why This Calculation Matters

Understanding the total volume in concentration-based mixtures is essential in industries such as beverage production, pharmaceuticals, and chemical processing. Whether scaling up a recipe or maintaining consistent batch quality, accurate volume calculations ensure safety, compliance, and reliability.

Conclusion

If 15 liters of alcohol make up 20% of the total solution, the complete mixture contains 75 liters—15 liters of pure alcohol blended with 60 liters of water. This clear, formulaic approach enables quick and confident calculations every time.

Keywords: alcohol solution, water mixture, 20% alcohol concentration, total volume calculation, percentage mixture, how to calculate solution volume, 15 liters alcohol, 80% water mixture, dilution calculation.