SOLUTION: melissa invested a sum of money at 3% annual simple interest. she invested three times that sum of 5% annual simple interest. if her total yearly interest from both investments was

Algebra.Com
Question 977334: melissa invested a sum of money at 3% annual simple interest. she invested three times that sum of 5% annual simple interest. if her total yearly interest from both investments was $3600, how much was invested at 3%?
Answer by richwmiller(17219)   (Show Source): You can put this solution on YOUR website!
Total yearly interest for the two accounts is: $3600
x=3y+0
0.05*x+0.03*y=3600
Substitute for x
0.05*(3y+0)+0.03*y=3600
Multiply out
0.15y+0+0.03*y=3600
Combine like terms.
0.15y+0+0.03*y=3600
0.15y+0.03*y=3600-0
0.18*y=3600
Isolate y
0.18*y=3600
y=3600/0.18
y=$20000 at 3%
y rounded off
y=$ 20000.00 at 3%
x=3y+0
x=3*20000+0
x=60000+0
x=$60000 at 5%
x rounded off
x=$ 60000.00 at 5%
x=$60000.00 at 5%
y=$20000.00 at 3%
Check
0.05*60000+0.03*20000=3600
3000+600=3600
3600=3600
If this statement is TRUE and neither x nor y is negative then all is well
codeinttm

RELATED QUESTIONS

Melissa invested a sum of money at 3% annual simple interest. She invested three times... (answered by checkley75)
Melissa invested a sum of money at 3% annual simple interest. She invested three times... (answered by mananth)
Melissa invested a sum of money at 3% annual simple interest. She invested three times... (answered by stanbon)
Melissa invested a sum of money at 3% annual interest. She invested three times that sum... (answered by checkley77)
Melissa invested a sum of money at 3% annual interest. She invested three times that sum... (answered by John10)
melissa invested a sum of money at 4% annual interest. she invested three times that sum... (answered by ewatrrr)
Bruce Blossom invested a sum of money at 10% annual simple interest and invested twice... (answered by josmiceli)
Trudy Waterbury, a financial planner, invested a certain amount of money at 9% annual... (answered by checkley71)
A person invested a sum of money at 9% annual simple interest and invested twice that... (answered by ankor@dixie-net.com)