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| Question 692100:  You invest $40,000 in two funds paying 3% and 4 1/2% simple interest. The total annual interest is $1650. How much do you invest in each fund?
 Answer by stanbon(75887)
      (Show Source): 
You can put this solution on YOUR website! You invest $40,000 in two funds paying 3% and 4 1/2% simple interest. The total annual interest is $1650. How much do you invest in each fund? ---------
 Quantity Eq: t + f = 40,000 dollars
 Interest Eq:0.03t + 0.045f = 1650 dollars
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 Multiply thru top eq. by 30
 Multiply thru bottom eq. by 1000
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 30t + 30f = 30*40,000
 30t + 45f = 1650000
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 Subtract and solve for "f":
 15f = 450000
 f = $30,000 (amt invested at 4.5%
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 Solve for "t" usiing t + f = 40,000
 t = $10,000 (amt. invested at 3%)
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 Cheers,
 Stan H.
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