Donna invested her 33K bonus and received a total of $970 in interest after 1 year. If part of the money returned 4% and the remainder 2.25%, then how much did she invest at each rate?
2007-04-07 13:59:37 · 3 answers · asked by Shareen 2 in Science & Mathematics ➔ Mathematics
Solve this equation:
.04x + .0225(33000 - x) = 970
.04x + 742.50 - .0225x = 970
.04x - .0225x = 970 - 742.50
.0175x = 227.5
x = 227.50 / .0175
x = $13,000
Donna invested $13,000 at 4% and $20,000 at 2.25%.
2007-04-07 14:02:47 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Let x = amount that returned 4%
Let y = amount that returned 2.25%
Start with two equations:
x + y = $33,000 or x = $33,000 - y
0.04x + 0.0225y = $970
Simplify into one equation:
0.04(33,000 - y) + 0.0225y = 970
1320 - 0.04y + 0.0225y = 970
1320 - 0.0175y = 970
0.0175y = 350
y = 20,000
and x = 33,000 - 20,000 = 13,000
2007-04-07 21:17:42 · answer #2 · answered by flipshine 2 · 0⤊ 0⤋
x= amount invested at 4%
33,000 - x = amount invested at 2.25%
So .04x +.0225(33,000-x) = 970.
.04x + 742.5-.0225x = 970
.0175x = 227.5
x = 227.5/.0175 = $13,000 = amount invested at 4%
So 33,000 -13,000 = $20,000 = amount invested at 2.25%
2007-04-07 21:12:01 · answer #3 · answered by ironduke8159 7 · 0⤊ 0⤋