Question 1148679
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Here is a quick alternative to the standard algebraic solution method shown by the other tutor  (assuming, of course, that an algebraic solution method is not required....)<br>
(1) 17% is 2/3 of the way from 11% to 20%.  (Picture the three percentages on a number line -- 11, 17, and 20.  11 to 20 is 9; 11 to 17 is 6; 6 is 2/3 of 9.)<br>
(2) That means 2/3 of the mixture must be the higher percentage ingredient.<br>
ANSWER: 2/3 of 57ml, or 38ml, of the 20% acid solution; the other 19ml of the 11% acid solution.<br>