<PRE><B>Question 1044621</B>
An alloy is a mixture of metals. Suppose that a certain alloy is made by mixing 
100 grams of an alloy that contains 28% copper with 28 grams of pure copper.
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How many grams of copper are in the resulting mixture?
128
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what percentage of the resulting mixture is copper?
P = percentage
100*28 + 28*100 = P*128
P = 5600/128 = 43.75%</PRE>