Question 275411
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The responses you have received so far all use the standard formal algebraic method for solving the problem -- writing and solving an equation which says the sum of the amounts of silver iodide in the two ingredients is equal to the amount in the mixture.<br>
If a formal algebraic solution is needed, then that is the standard method and almost certainly the fastest formal method.<br>
But 2-part mixture problems like this can be solved much faster using an informal method using the ratio of the amounts of the two ingredients.<br>
Here in words is the solution to this problem using this method.<br>
(1) The target 6% solution is "twice as close to 4% as it is to 10%" (the difference between 4% and 6% is 2%; the difference between 6% and 10% is 4%.)
(2) That means the amount of 4% silver iodide in the mixture must be twice as much as the amount of 10% silver iodide.
(3) The mixture uses 6 liters of the 4% silver iodide, so it must use 3 liters of the 10% silver iodide.<br>
ANSWER: 3 liters<br>