please help

kristin

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Dec 7, 2005
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help on a word problem, please, not even sure on how to start....

Chemistry:: How many ounces of pure water must be added to 40oz of a 20% salt solution to make a salt somution that is 5% salt.



also, could you help with this one:::

Simplify::sqare root 2a^9b (all in the square root) * square root 98ab^3 (under the whole square root) * square root 2a (2a under the square root). could you help please? Thanks
 
kristin said:
help on a word problem, please, not even sure on how to start....

Chemistry:: How many ounces of pure water must be added to 40oz of a 20% salt solution to make a salt somution that is 5% salt.
Equate something, either salt or water, in this case.

First, Name stuff. X oz = amount of water that must be added.

Equate Salt

(40 oz * 20%) + (X oz * 0%) = [(40+X) oz * 5%]

Equate Water

(40 oz * 80%) + (X oz * 100%) = [(40+X) oz * 95%]
 
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