document.write( "Question 1160573: A woman has a total of $10,000 to invest. She invests part of the money in an account that pays 8% per year and the rest in an account that pays 11% per year. If the interest earned in the first year is $890, how much did she invest in each account? \n" ); document.write( "
Algebra.Com's Answer #783908 by greenestamps(13200)![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "Formal algebra.... \n" ); document.write( "x amount at 8%; 10000-x at 11%; total interest 890: \n" ); document.write( " \n" ); document.write( "Solve using basic algebra; I leave that to you. \n" ); document.write( "A much faster and easier informal solution method.... \n" ); document.write( "(1) $10,000 all at 8% would yield $800 interest; all at 11% would yield $1100 interest. \n" ); document.write( "(2) The actual interest amount, $890, is 3/10 of the way from $800 to $1100. ($800 to $1100 is $300; $800 to $890 is $90; 90/300 = 3/10). \n" ); document.write( "(3) That means 3/10 of the $10,000 was invested at the higher rate. \n" ); document.write( "ANSWER: 3/10 of $10,000, or $3000, at 11%; the rest at 8%. \n" ); document.write( "CHECK: .11(3000)+.08(7000) = 330+560 = 890 \n" ); document.write( " \n" ); document.write( " |