<PRE><B>Question 293030</B>
A 12-quart cooling system is tested and found filled with a 60% antifreeze solution.
 The ideal solution should be a 50% antifreeze solution.
 How many quarts of solution needs to be drained and replaced with pure water to reach the ideal mixture?
:
Let x = amt of solution to be removed and also amt of water to be added
:
.60(12-x) = .50(12)
:
7.2 - .6x = 6
:
-.6x = 6 - 7.2
:
-.6x = -1.2
x = {{{1.2/.6}}}
x = 2 qt of 60% solution removed and 2 qt of water added
:
:
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