Amanda invested a total of $3,600 into three separate accounts that pay 5%, 7%, and 9% annual interest. Amanda has four times as much invested in the account that pays 9% as she does in the account that pays 5%. If the total interest for the year is $282, how much did Amanda invest in each account?

Question

Amanda invested a total of $3,600 into three separate accounts that pay 5%, 7%, and 9% annual interest.  Amanda has four times as much invested in the account that pays 9% as she does in the account that pays 5%.  If the total interest for the year is $282, how much did Amanda invest in each account?

Steve · Accepted Answer

let x be the amount at 5% 4x at 9% 3600-(x+4x) at 7% .05x + .09*4x + .07(3600-5x) = 282 .05x + .36x + 252 - .35x = 282 .06x = 30 x = 500 so, she has 500 at 5% 2000 at 9% 1100 at 7%