SOLUTION: Melissa invested a sum of money at 3% annual simple interest. She invested three times that sum at 5% annual simple intrest. If her total yearly intrest from both investments was $

Algebra ->  Percentages: Solvers, Trainers, Word Problems and pie charts -> SOLUTION: Melissa invested a sum of money at 3% annual simple interest. She invested three times that sum at 5% annual simple intrest. If her total yearly intrest from both investments was $      Log On


   

Question 21038: Melissa invested a sum of money at 3% annual simple interest. She invested three times that sum at 5% annual simple intrest. If her total yearly intrest from both investments was $3600, how much was invested at 3%?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Let "x" be the amount invested at 3%
Then "3x" is the amount invested at 5%
Equation:
0.03x + 0.05(3x) = 3600
3x + 15x = 360000
18x = 360000
x = $20,000 (amount invested at 3%)
3x = $60,000 (amount invested at 5%)
Cheers,
Stan H.