SOLUTION: The radiator in the car is filled with a solution of 60% antifreeze and 40% water. The manufacturer of the aniotifreeze suggests that, for summer driving, optimal cooling of the en

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Question 816165: The radiator in the car is filled with a solution of 60% antifreeze and 40% water. The manufacturer of the aniotifreeze suggests that, for summer driving, optimal cooling of the engine is obtained with only 50% antifreeze. If the capacity of the radiator is 3.6 L, how much coolant should be drained and replaced with water to reduce the antifreeze concentration to the recommended level?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+.6%2A3.6+=+2.16+ L antifreeze
originally in radiator
Let +x+ = liters of solution to
be drained and replaced with water
+.6x+ = liters of antifreeze
drained from radiator
-------------------------
+%28+2.16+-+.6x+%29+%2F+3.6+=+.5+
Note that you start with 3.6 liters
and end with 3.6 liters
+2.16+-+.6x+=+.5%2A3.6+
+.6x+=+2.16+-+1.8+
+.6x+=+.36+
+x+=+.6+
.6 liters must be drained and replaced with
pure water
----------------
check:
+.6%2A.6+=+.36+ liters of alcohol is drained
There is +3.6%2A.6+-+.36+
+2.16+-+.36+=+1.8+ liters alcohol left
-----------------
+.6+ liters of water is added to make
+1.8+ liters alcohol and +3.6+-+1.8+=+1.8+
liters water
They are 50% - 50%
OK