<PRE><B>Question 1096481</B>
A scientist mixes water (containing no salt) with a solution that contains 
40%  salt. She wants to obtain 200 ounces of a mixture that is 5% salt. How many ounces of water and how many ounces of the 40% salt solution should she use
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W = Water
S = 40% salt (if available)
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W + S = 200
W*0 + S*40 = (W+S)*5
40S = 5W + 5S
5W = 35S
W = 200-S
5(200-S) = 35S
1000 - 5S = 35S
40S = 1000
S = 25
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