SOLUTION: an alloy of gold,silverand bronze contain 90% bronze, 7% gold and3% silver.a second alloy of bronze and silver only is melted with the first and mixture contain 85% of bronze,5% of

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Question 970459: an alloy of gold,silverand bronze contain 90% bronze, 7% gold and3% silver.a second alloy of bronze and silver only is melted with the first and mixture contain 85% of bronze,5% of gold,10% of silver find the percentage of bronze in second alloy?

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
I will say that the quantity of metal that I
start out with is 100 units ( the units don't
matter -I can make them up )
----------------------------
That means I start with 90 units of bronze,
7 units of gold, and 3 units of silver
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Now I will say there are +a+ units of the
2nd mixture where +a+ could be any number
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In the 2nd mixture, there is:
+.85a+ units of bronze
+.05a+ units pf gold
+.1a+ units of silver
------------------------
The amount of gold did not change, so
+.05a+=+7+
+a+=+140+ units of final mixture
---------------
+.85a+=+.85%2A140+
+.85a+=+119+ units of bronze
------------------
+.1a+=+.1%2A140+
+.1a+=+14+ units of silver
------------------
I started with 90 units of bronze, and
ended up with 119, so there were
+119+-+90+=+29+ units of bronze
in the 2nd mixture
+140+-+100+=+40+ units in 2nd mixture
-------------------------
+29+%2F+40+=+.725+
There is 72.5% bronze in the 2nd mixture
-------------------------------------
check the answer:
Silver:
+.1%2A140+=+14+
+14+-+3+=+11+
+11%2F40+=+.275+
-------------------
+.725+%2B+.275+=+1+
correct, because no additional gold was added
Hope you can follow this and it makes sense