SOLUTION: A certain automatic soldering machine requires a solder containing half tin and half lead. How much pure tin must be added to 52 kg of a solder containing 62% lead and 38% tin to r

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Question 1056298: A certain automatic soldering machine requires a solder containing half tin and half lead. How much pure tin must be added to 52 kg of a solder containing 62% lead and 38% tin to raise the tin content to 50%?

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +x+ = kg of pure tin to be added
+.38%2A52+=+19.76+ = kg of pure tin in
the original 52 kg of solder
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+%28+x+%2B+19.76+%29+%2F+%28+x+%2B+52+%29+=+.5+
+x+%2B+19.76+=+.5%2A%28+x+%2B+52+%29+
+x+%2B+19.76+=+.5x+%2B+26+
+.5x+=+6.24+
+x+=+12.48+
12.48 kg of pure tin must be added
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check:
+%28+x+%2B+19.76+%29+%2F+%28+x+%2B+52+%29+=+.5+
+%28+12.48+%2B+19.76+%29+%2F+%28+12.48+%2B+52+%29+=+.5+
+32.24+%2F+64.48+=+.5+
+32.24+=+32.24+
OK