document.write( "Question 1105732: A person got 100000 dollar when he retired from service. He deposited some of that amount of money in bank and rest of his money in the post office and got 5400 dollar in total per year as interest .If the rate of simple interest per annum in the bank and in the post office are 5% and 6% respectively then let us write by calculating the money he had deposited in the bank and post office. \n" ); document.write( "

Algebra.Com's Answer #720626 by ikleyn(52781) $\"\"$ $\"About$

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document.write( "    B +     P = 10000,     (1)   (\"Bank + Post = 100000\")\r\n" );
document.write( "0.05B + 0.06P =  5400.     (2)   (interest + interest = total interest)\r\n" );
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document.write( "Simplify by multiplying eq(2) by 100 (both sides):\r\n" );
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document.write( " B +  P = 100000           (3)\r\n" );
document.write( "5B + 6P = 540000           (4)\r\n" );
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document.write( "Multiply eq(3) by 5 (both sides). Keep eq(4) as is. You will get\r\n" );
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document.write( "5B + 5P = 500000           (5)\r\n" );
document.write( "5B + 6P = 540000           (6)\r\n" );
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document.write( "Now subtract eq(5) from eq(6) (both sides). You will get\r\n" );
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document.write( "6P - 5P = 540000-500000,   or\r\n" );
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document.write( "P = 40000.\r\n" );
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document.write( "Answer.  $40000 was invested to the post office at 6% and the rest $60000 was invested to the bank at 5%.\r\n" );
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document.write( "Check.   0.05*60000 + 0.06*40000 = 5400 dollars.   ! Correct !\r\n" );
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\n" ); document.write( "\n" ); document.write( "Solved. // I used the Elimination method to solve the system of 2 equations. \r
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\n" ); document.write( "To see other similar solved problems on investment, look into the lesson\r
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