Joan Arlington has twice as much money invested at 5% simple annual interest as she does at 4%. If her yearly income from the two investments is
$224224 ,
how much does she have at each rate?
Let the amount invested @ 4% = F The amount invested @ 5% =2F
0.04F + 0.10F = 224 0.14F = 224 F = 224 / 0.14
F = $1,600 - amount invested @ 4% $1,600 * 2 =$3,200 - amount invested @ 5%.