Question 486071
1x.65=.65
.75n+(.75-.5)(1-n)=.65
.75n+.25-.25n=.65
.5n=.40
n=.40/.5=.8
1-n=.2
.75(.8)=.6
+.25(.2)=.05
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"""""""".65
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.2 gallons must be drained off and replaced by .50 alcohol to make the mix..