How many quarts of pure antifreeze must be added to 3 quarts of a 20% antifreeze solution to obtain a 40% antifreeze solution

Answer 1

If we have 3 quarts of 20% antifreeze, then we have (0.2)(3 quarts) = 0.6 quarts pure antifreeze in our initial solution. We want to find how many quarts of pure antifreeze we need before we have a 40% solution.

Let's start adding antifreeze. The percentage of solution that is antifreeze can be represented by

% antifreeze = (antifreeze volume)/(total fluid volume)

0.4 = (0.6 quarts + x) / (3 quarts + x), where x is the amount of pure antifreeze we add.

0.4(3 quarts + x quarts) = (0.6 quarts + x)

1.2 + 0.4x = 0.6 + x

0.6 = 0.6x

x = 1 quart

Let me know if that makes sense, the set up can be tricky! If you have other questions send me a direct message and I'll help you out with them.

-Ethan