Question 905723
A tank contains 10L of 25% solution of alcohol. How much must be taken from the tank to be replaced by a 5% solution of alcohol so that the vessel will now contain a 10% solution of alcohol?
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let x=amt of 25% solution to be taken out and replaced by a 5% solution.
25%(10-x)+5%x=10%*10
2.5-.25x+.05x=1
.20x=1.5
x=7.5
amt of 25% solution to be taken out and replaced by a 5% solution. 7.5L