SOLUTION: A total of $18,000 is invested in two corporate bonds that pay 3.5% and 5% simple interest. The investor wants an annual interest income of $750 from the investments. What amount s

Algebra ->  Customizable Word Problem Solvers  -> Finance -> SOLUTION: A total of $18,000 is invested in two corporate bonds that pay 3.5% and 5% simple interest. The investor wants an annual interest income of $750 from the investments. What amount s      Log On

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Question 869888: A total of $18,000 is invested in two corporate bonds that pay 3.5% and 5% simple interest. The investor wants an annual interest income of $750 from the investments. What amount should be invested in the 3.5% bond?
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
Part I 3.50% per annum ------------- Amount invested =x
Part II 5.00% per annum ------------ Amount invested = y
18000
Interest----- 750.00

Part I 3.50% per annum ---x
Part II 5.00% per annum ---y
Total investment
x + 1 y= 18000 -------------1
Interest on both investments
3.50% x + 5.00% y= 750
Multiply by 100
3.5 x + 5 y= 75000.00 --------2
Multiply (1) by -3.5
we get
-3.5 x -3.5 y= -63000.00
Add this to (2)
0 x 1.5 y= 12000
divide by 1.5
y = 8000
Part I 3.50% $ 10000
Part II 5.00% $ 8000

CHECK
10000 --------- 3.50% ------- 350.00
8000 ------------- 5.00% ------- 400.00
Total -------------------- 750.00

m.ananth@hotmail.ca