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# Pharmacy calculation help please. watch

1. A student possesses brandy containing 42%v/v ethanol and wine containing 10% ethanol. What volume of brandy should be diluted with the wine to produce 150ml of a cordial containing 15% ethanol? Report the answer to the nearest 1ml.

How do I work this out?
2. Misread the question
3. (Original post by Ateo)
What are the volumes of brandy and wine?
It's not given.
4. (Original post by sultryabyss)
It's not given.
Oops, I interpreted the question incorrectly. You do this by ratios.

Let be volume of brandy and be the volume of wine both in ml. Then:

(1)

Also we want 15% concentration at the end, thus:

(2)

Solve (1) and (2) simultaneously.

Why on earth would you dilute brandy?

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Updated: May 12, 2013
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