Respuesta :
Answer:
Phyllis invested $9000 at the rate of 5.25% and $4000 at the rate of 5%.
Step-by-step explanation:
Formula for the simple interest is,
Interest = [tex]\frac{P\times r\times t}{100}[/tex]
Here, P = Principal amount
r = rate of interest
t = Duration of investment
Let Phyllis invested amount (at 5.25% rate of interest) = $x
Therefore, Interest on this amount,
Interest = [tex]\frac{5.25\times x}{100}[/tex]
= $0.0525x
If he invested the rest amount $(13000 - x) at the rate of 5%,
Interest earned on this amount = [tex]\frac{(13000-x)\times 5\times 1}{100}[/tex]
= $(650 - 0.05x)
Interest earned on total amount = $672
Therefore, $0.0525x + $(650 - 0.05x) = $672.5
0.0025x + 650 = 672.5
0.0025x = 22.5
x = $9000
Rest amount = 13000 - 9000
= $4000
Phyllis invested $9000 at the rate of 5.25% and $4000 at the rate of 5%.
