Donna invested her $33,000 bonus and received $970 in interest after one year. If part of the money returned 4% and the rest earned 2.25%, how much did she invest at each rate?
2007-09-14 14:58:21 · 3 answers · asked by Mariana C 1 in Science & Mathematics ➔ Mathematics
Let x = amount invested at 4%, $33,000.00 - x = amount invested at 2.25%
Amount invested at 4%:
0.04x + 0.0225($33,000.00 - x) = $970.00
0.04x + $742.50 - 0.0225x = $970.00
0.0175x = $227.50
x = $13,000.00
Amount invested at 2.25%:
= $33,000.00 - $13,000.00
= $20,000.00
Answer: $13,000.00 @ 4%, $20,000.00 @ 2.25%
Proof (Interest earned):
= (0.04 * $13,000.00) + (0.0225 * $20,000.00)
= $520.00 + $450.00
= $970.00
2007-09-14 15:13:07 · answer #1 · answered by Jun Agruda 7 · 3⤊ 0⤋
Call x the amount invested at 2.25%. Therefore 33000-x is invested at 4%.
Write total return is (33000-x)*0.04+x*0.025=970
Sole this for x to get the amount invested at 2.25 percent. Remeber to answer the question fully and also state the amount invested at 4%.
2007-09-14 15:06:49 · answer #2 · answered by Anonymous · 0⤊ 0⤋
x + y = 33,000
.04x + .0225y = 970
4x + 2.25y = 97,000
16x +9y = 388,000
from the first 9x + 9y = 297,000
7x = 91,000
x = 13,000
y = 20,000
2007-09-14 15:09:21 · answer #3 · answered by Beardo 7 · 0⤊ 0⤋