Problema Solution
THe cooling system of a car has a capacity of 25 liters. If the system is currently filled with a mixture that is 50% antifrerze, how much of that mixture should be drained and replaced with pure antifreeze so that the system is filled with a solution of 90% antifreeze?
Answer provided by our tutors
at the beginning the antifreeze is 50%
so it has 50% * 25 = 12.5 liters
it changes to 90% it means need 90% * 25 = 22.5 liters
so 10 liters should be drained and replaces with pure antifreeze