Question 1109169
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Tutor addingup worked the wrong problem; he added more of the other ingredient to make the solution 40% water.<br>
Tutor teachmath gave his usual useless response -- a right answer with no work shown.  That's a strange way of "teaching" math.<br>
Tutor teachmath: if you are by chance reading this, please stop providing useless answers to people who are nearly always interested in learning HOW to solve a problem -- not just in seeing the answer.<br>
The other tutor provided a valid solution to the problem.<br>
My approach would be slightly different:<br>
The 500mL is 52% water, so it is 48% of the other ingredient.
48% of 500mL is 240mL.
If the final solution is to be only 40% water, it must be 60% of the other ingredient.
If 60% of the final mixture is the original 240mL of the other ingredient, then the volume of the final mixture is 240/.60 = 400mL.
So, since the original mixture was 500mL, 100mL of water needs to be removed.