SOLUTION: A total of $20,000 is invested in two corporate bonds that pay 3.5% and 5% simple interest. The investor wants an annual interest income of $790 from the investments. What amount s

Question 866206: A total of $20,000 is invested in two corporate bonds that pay 3.5% and 5% simple interest. The investor wants an annual interest income of $790 from the investments. What amount should be invested in the 3.5% bond?
Answer by mananth(16946) (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
20000
Interest----- 790.00

Part I 3.50% per annum ---x
Part II 5.00% per annum ---y
Total investment
x + 1 y= 20000 -------------1
Interest on both investments
3.50% x + 5.00% y= 790
Multiply by 100
3.5 x + 5 y= 79000.00 --------2
Multiply (1) by -3.5
we get
-3.5 x -3.5 y= -70000.00
Add this to (2)
0 x 1.5 y= 9000
divide by 1.5
y = 6000
Part I 3.50% $ 14000
Part II 5.00% $ 6000

CHECK
14000 --------- 3.50% ------- 490.00
6000 ------------- 5.00% ------- 300.00
Total -------------------- 790.00

m.ananth@hotmail.ca

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