SOLUTION: I am having a problem setting this question up to solve Jolene invests her savings in two bank accounts, one paying 3 percent and the other paying 8 percent simple interest per

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: I am having a problem setting this question up to solve Jolene invests her savings in two bank accounts, one paying 3 percent and the other paying 8 percent simple interest per      Log On


   



Question 509643: I am having a problem setting this question up to solve
Jolene invests her savings in two bank accounts, one paying 3 percent and the other paying 8 percent simple interest per year. She puts twice as much in the lower-yielding account because it is less risky. Her annual interest is 6076 dollars. How much did she invest at each rate?
thanks :)

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Let S = the total amount of Jolene's savings.
She invests two thirds of S in the bank that pays 3% interest and the remaining one third of S in the bank that pays 8% interest.
So we can write the equation that relates the interest amounts earned at each bank to the total amount of interest earned ($6,076).
%282%2F3%29S%280.03%29+%2B+%281%2F3%29S%280.08%29+=+6076 It will make the calculations a little easier if we change the interest rates to fractions.
3% = 0.03=3%2F100 and 8%=0.08+=+8%2F100
%282%2F3%29S%283%2F100%29%2B%281%2F3%29S%288%2F100%29+=+6076 Now simplify the left side of the equation.
2S%2F100+%2B+8S%2F300+=+6076 Add the fractions.
%286S%2B8S%29%2F300+=+6076 Simplify.
14S%2F300+=+6076 Multiply both sides by 300.
14S+=++1822800 Divide both sides by 14.
S+=+130200
Jolene's total invested savings is:
$130,200
Two thirds of this are invested at 3%, so...
0.03%282%2F3%29%28130200%29+=+%283%2F100%29%282%2F3%29%28130200%29=%282%2F100%29%28130200%29+=+2604
$2,604 interest was earned at 3% per annum.
One third of $130,200 was invested at 8%, so...
0.8%281%2F3%29%28130200%29+=+%288%2F100%29%281%2F3%29%28130200%29%29=%288%2F300%29%28130200%29+=+3472
$3,472 interest was earned at 8% per annum.
The the total interest is:
2604%2B3472+=+6076 = $6,076