document.write( "Question 1159977: the water level was 15 milliliters before adding the chain, and 20 milliliters after adding the chain. When I weighed the chain, its mass was 66.7 grams.\r
\n" ); document.write( "\n" ); document.write( "I believe the chain is solid metal (not gold plated), but is probably a blend of gold and other metals. I looked up that gold has a density of 19.3 g/ml, while the other metals like silver and copper usually blended with gold have a combined density of about 9.7 g/ml.\r
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Algebra.Com's Answer #783127 by ikleyn(52864) $\"\"$ $\"About$

You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "Hey, water level IS NOT MEASURED in milliliters (!) (!) (!)\r
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\n" ); document.write( "\n" ); document.write( "This (or similar) problems go after Archimedes famous idea \"Eureka ! --- Found (!)\".\r
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\n" ); document.write( "\n" ); document.write( "( see the links\r
\n" ); document.write( "\n" ); document.write( "https://www.scientificamerican.com/article/fact-or-fiction-archimede/\r
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\n" ); document.write( "\n" ); document.write( "https://www.livescience.com/58839-archimedes-principle.html )\r
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\n" ); document.write( "\n" ); document.write( "Now see, how the problem SHOULD be formulated.\r
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document.write( "    The alloy (gold and some other metal) has the volume of 5 cubic centimetres and the mass of 66.7 grams.\r\n" );
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document.write( "    The gold density is 19.3 g/cm^3, while the other metal's density is 9.7 g/cm^3.\r\n" );
document.write( "    Determine what percentage of the alloy is gold, by mass, to at least 1 decimal place?\r\n" );
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document.write( "       +-----------------------------------------------------+\r\n" );
document.write( "       |   All the rest in your formulation is bla-bla-bla   |\r\n" );
document.write( "       |    with the only goal to confuse the reader . . .   |\r\n" );
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document.write( "Let x be the mass of the gold in the chain and y be the mass of the other metal.\r\n" );
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document.write( "Then you have this system of 2 equations\r\n" );
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document.write( "    x + y = 66.7      (grams; the total mass)     (1)\r\n" );
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document.write( "     +  = 5   (cm^3; the total volume)     (2)\r\n" );
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document.write( "Solve the system and get the answer.\r\n" );
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document.write( "            x +         y = 66.7        (3)\r\n" );
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document.write( "    0.051813x + 0.103093y =  5          (4)\r\n" );
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document.write( "Now, instead of solving manually, I will employ an online solver  www.reshish.com .\r\n" );
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document.write( "The answer it provides for x (the mass of gold) is 36.589 grams (with three decimals).\r\n" );
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document.write( "It is   = 0.549 part of the alloy by mass, or  54.9%    ANSWER\r\n" );
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