Question

There are 25 quarts of 20% anti freeze solution in the radiator of a car. How many quarts of anti freeze must be added to make a 50% anti freeze solution

Answer 1

The way the question stands, it makes no sense.
You would have to drain some of the solution and then add pure antifreeze.

does it ask:
How much of the current antifreeze, which is 20% , must be drained and the topped up with 100% antifreeze to have a 50% antifreeze ?

Please confirm before I answer