document.write( "Question 1020441: Christin Demin invested part of her P240,000 in a firm that pays 12% per annum while the rest in a company that pays 7% per annum. If by the end of a year the two investments yielded a total interest of P21,600 how much was invested at each rate? \n" ); document.write( "

Algebra.Com's Answer #636356 by stanbon(75887) $\"\"$ $\"About$

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Christin Demin invested part of her P240,000 in a firm that pays 12% per annum while the rest in a company that pays 7% per annum. If by the end of a year the two investments yielded a total interest of P21,600 how much was invested at each rate?
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\n" ); document.write( "Equations:
\n" ); document.write( "Quantity:: t+s = 240,000
\n" ); document.write( "Interest::12t+7s = 2160000
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\n" ); document.write( "Modify for elimination::
\n" ); document.write( "7t + 7s = 7*240000
\n" ); document.write( "12t + 7s = 2160000
\n" ); document.write( "-----------------------
\n" ); document.write( "Subtract and solve for \"t\"::
\n" ); document.write( "5t = 480000
\n" ); document.write( "---
\n" ); document.write( "t = 96000 (amt. invested at 12%)
\n" ); document.write( "s = 240000-96000 = 144000 (amt invested at 7%)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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