SOLUTION: Jess invested $30 more at 6% than at 5%. If the total annual interest is $100, how much is invested at each rate? I've tried working this out but to know avail. I'm helping my

Algebra ->  Percentages: Solvers, Trainers, Word Problems and pie charts  -> Lessons -> SOLUTION: Jess invested $30 more at 6% than at 5%. If the total annual interest is $100, how much is invested at each rate? I've tried working this out but to know avail. I'm helping my       Log On


   

Question 195256: Jess invested $30 more at 6% than at 5%. If the total annual interest is $100, how much is invested at each rate?
I've tried working this out but to know avail. I'm helping my son and I'm lost. Thanks
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Jess invested $30 more at 6% than at 5%. If the total annual interest is $100, how much is invested at each rate?
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Equations:
Quantity Eq. : x = y + 30
Interest Eq. :0.06x + 0.05y = 100
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Substitute:
0.06(y+30) + 0.05y = 100
Multiply thru by 100 to get:
6(y+30) + 5y = 10000
6y + 180 + 5y = 10000
11y = 9820
y = $892.73 (amount invested at 5%)
x = y + 30 = 892.73 + 30 = $922.73 (amount invested at 6%)
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Cheers,
Stan H.