Question

Sally invested some money at15 % interest. Sally also invested$203 more than4 times that amount at8 % . How much is invested at each rate if Sally receives$2017.03 in interest after one year? (Round to two decimal places if necessary.)

Answer 1

Investments and percentages

Sally has two investments:

x at 15% of interest

4x+$203 at 8% of interest

Each month she is receiving

0.15x+0.08(4x+$203)=0.15x+0.32x+$16.24

=0.47x+$16.24

Then, the whole year she received

=12(0.47x+$16.24)

since we know that after onw year she received $2017.03

then

$2017.03 = 12(0.47x+$16.24)

Now we just must find x

0.47x+$16.24 = $2017.03/12

= $168.085

0,47x = $168,085-$16,24

= $152,085

Therefore x = $323,58 is the amount of money of her first investment

Since the second investment's is given by 4x+$203

then the amount of money of her second investment is $1 310,56