document.write( "Question 1046867: how many pounds of 60-40 solder (60% tin, 40% lead) must be mixed with 40-60 solder to produce 60 grams of 55-45 solder?\r
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Algebra.Com's Answer #662398 by ikleyn(52790) $\"\"$ $\"About$

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\n" ); document.write( "how many pounds of 60-40 solder (60% tin, 40% lead) must be mixed with 40-60 solder to produce 60 grams of 55-45 solder?
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document.write( "Let x be \"how many pounds of 60-40 solder (60% tin, 40% lead) must be mixed\".\r\n" );
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document.write( "Then the governing equation is\r\n" );
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document.write( "0.6x + 0.4(60-x) = 0.55*60,  or\r\n" );
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document.write( "0.6x + 24 - 0.4x = 33,  or\r\n" );
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document.write( "0.2x = 33 - 24,\r\n" );
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document.write( "0.2x = 9,\r\n" );
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document.write( "x =  = 45.\r\n" );
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document.write( "Answer. Mix 45 gram of 60-40 solder with 60-45 = 15 gram of 40-60 solder.\r\n" );
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document.write( "Check by tin.   0.6*45 + 0.4*15 = 33.  0.55*30 = 33.  Correct! \r\n" );
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document.write( "Check by lead.  0.4*45 + 0.6*15 = 27.  0.55*60 = 27.  Correct! \r\n" );
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