document.write( "Question 1164248: You invested $5000 between two accounts paying 3% and 7% annual interest, respectively. If the total interest earned for the year was $190 how much was invested at each rate of 3% and 7%? \n" ); document.write( "
Algebra.Com's Answer #788552 by greenestamps(13200)![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "(1) A typical formal algebraic setup for solving the problem: \n" ); document.write( "x amount at 3%, plus ($5000-x) amount at 7%, yields $190 interest. \n" ); document.write( " \n" ); document.write( "Solve using basic algebra; I leave that to you. \n" ); document.write( "(2) A quick and easy way to solve any two-part \"mixture\" problem like this, if a formal algebraic solution is not required: \n" ); document.write( "$5000 all invested at 3% would yield $150 interest; all at 7$ would yield $350 interest. \n" ); document.write( "The actual interest, $190, is 40/200 = 1/5 of the way from $150 to $350. (If it helps, picture the three dollar amounts 150, 190, and 350 on a number line; 150 to 190 is a difference of 40, 150 to 350 is a difference of 200, so 190 is 40/200 = 1/5 of the distance from 150 to 350.) \n" ); document.write( "That means 1/5 of the total was invested at the higher rate. \n" ); document.write( "ANSWER: 1/5 of the $5000, or $1000, at 7%; the other $4000 at 3%. \n" ); document.write( "CHECK: .03(4000)+.07(1000) = 120+70 = 190 \n" ); document.write( " \n" ); document.write( " |