Question 1184175
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The response from the other tutor is not much help to a student who is trying to learn HOW to set up and solve this kind of problem....<br>
Let x be the number of quarts of 100% antifreeze to add.<br>
The antifreeze in the two ingredients is 100% of x quarts, plus 50% of the 4 quarts you started with; and it is 60% of the total (x+4) quarts:<br>
{{{100(x)+50(4)=60(x+4)}}}<br>
Solve using basic algebra... I leave that to you.<br>
If a formal algebraic solution is not required, here is a quick and easy way to solve any 2-part "mixture" problem like this.<br>
Picture the percentages of the two ingredients and the final mixture on a number line -- 50, 60, and 100; observe/calculate that 60% is 1/5 of the way from 50% to 100%. (50 to 100 is a difference of 50; 50 to 60 is a difference of 10; 10/50 = 1/5.)<br>
That means 1/5 of the mixture is the 100% antifreeze that you are adding.<br>
So the 4 quarts you started with is 4/5 of the mixture; that means the 1/5 of the mixture that you added is 1 quart.<br>
ANSWER: add 1 quart of 100% antifreeze<br>
CHECK:
.50(4)+1.00(1)=2+1=3
.60(5)=3<br>