document.write( "Question 1208045: Mr B invested p30000:part at 5% and part at 8%.The total interest on the investment was p2100. How much did she invest at each rate. \n" ); document.write( "

Algebra.Com's Answer #846176 by ikleyn(52781) $\"\"$ $\"About$

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\n" ); document.write( "Mr B invested p30000:part at 5% and part at 8%.
\n" ); document.write( "The total interest on the investment was p2100. How much did she invest at each rate.
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document.write( "x         invested at 8%;\r\n" );
document.write( "(30000-x) invested at 5%.\r\n" );
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document.write( "The total annual interest is 0.08x + 0.05(30000-x).\r\n" );
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document.write( "An equation to find x is\r\n" );
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document.write( "    0.08x + 0.05(30000-x) = 2100.\r\n" );
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document.write( "Simplify and find x\r\n" );
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document.write( "    0.08x + 1500 - 0.05x = 2100\r\n" );
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document.write( "    0.08x - 0.05x = 2100 - 1500\r\n" );
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document.write( "         0.03x    =     600\r\n" );
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document.write( "             x    =     600/0.03 = 20000.\r\n" );
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document.write( "ANSWER.  p20000 invested at 8%.  The rest,  p30000 - p20000 = p10000 invested at 5%.\r\n" );
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document.write( "CHECK.   0.08*20000 + 0.05*10000 = 2100 for the total annual interest.   ! precisely correct !\r\n" );
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