SOLUTION: a smelter ha 640 pounds of a 50% silver alloy and 200 pounds of a 20% alloy. how much of the 50% silver alloy must be mixed with all of the 20% alloy to give a 30% silver alloy?

Question 837016: a smelter ha 640 pounds of a 50% silver alloy and 200 pounds of a 20% alloy. how much of the 50% silver alloy must be mixed with all of the 20% alloy to give a 30% silver alloy?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
a smelter has 640 pounds of a 50% silver alloy and 200 pounds of a 20% alloy. how much of the 50% silver alloy must be mixed with all of the 20% alloy to give a 30% silver alloy?
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Equation:
silver + silver = silver
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0.50x + 0.20*200 = 0.30(x+200)
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50x + 20*200 = 30x + 30*200
20x = 10*200
x = 100 lbs (amt. of 50% alloy needed)
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Cheers,
Stan H.
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