A radiator holds 40 quarts of fluid. If the current mixture contains 25% anti-freeze, how
much fluid must be drained from the radiator so, when replaced with water, the new
mixture contains 10% anti-freeze?
A radiator holds 6 quarts of fluid. If the current mixture contains 50% anti-freeze, how
much fluid must be drained from the radiator so, when replaced with pure antifreeze, the
new mixture contains 80% anti-freeze?