<PRE><B>Question 1162826</B>
Let  x  be the volume of the pure water under the question, in mL.


Then the volume of the pure alcohol in 140 mL of the 65% alcohol solution is  0.65*140 mL.


The total volume after adding x mL of water is (140+x) mL.


The concentration equation for the resulting mixture after adding water is


    %280.65%2A140%29%2F%28140%2Bx%29 = 0.35.


From the equation, 


    0.065*140 = 0.35*(140+x)

    0.065*140 = 0.35*140 + 0.35x

    x = %28065%2A140+-+0.35%2A140%29%2F0.35 = 120 mL.


ANSWER.  120 mL of water should be added.


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Same problem, different numbers.
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