Question 1142915
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Short, quick path to the answer without formal algebra (for this or any of a number of similar "mixture" problems:<br>
16%is 6/15 = 2/5 of the way from 10% to 25% (10 to 25 is 15; 10 to 16 is 6; 6/15 = 2/5);
Therefore 2/5 of the mixture must be the 25% concentration.<br>
ANSWER: 2/5 of 20ml, or 8ml, of 25%; 12ml of 10%.