Answer: Bond A = $14,000
Bond B = ₦6,000
Explanation:
We can solve by setting up mathematical equations.
Let A and B be used to express the dollar amounts invested at 8% and 10% respectively.
Capital invested equation becomes A + B = 20,000 - - - - - eq 1
Percentage interest equation becomes 8% of A + 10% of B = 1,720
To remove percentages we multiply through by 100, which gives
8A + 10B = 172,000 - - - - - - eq 2
So we have two simultaneous equations.
To solve, we multiply eq 1 by 10 so by subtraction we can eliminate B, then solve for A. Eq 1 becomes
10A + 10B = 200,000 - - - - eq 3
Subtract eq 2 from eq 3
(10A - 8A) + (10B - 10B) = 200000 - 172000
2A = 28000
A = 28000/2 = $14,000
A + B = 20000 from eq 1
Now A is 14000
14000 + B = 20000
B = 20000 - 14000
B = $6,000
Therefore capital invested is $14000 for bond A and $6000 for bond B