SOLUTION: mardi received an inheritance of $70,000. she invested part at 7% and deposited the reminder in a 8%. her total annual income was $5300. Find the amount invested at 7%.

Algebra ->  Finance -> SOLUTION: mardi received an inheritance of $70,000. she invested part at 7% and deposited the reminder in a 8%. her total annual income was $5300. Find the amount invested at 7%.      Log On


   



Question 874587: mardi received an inheritance of $70,000. she invested part at 7% and deposited the reminder in a 8%. her total annual income was $5300. Find the amount invested at 7%.
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
Part I 7.00% per annum ------------- Amount invested =x
Part II 8.00% per annum ------------ Amount invested = y
70000
Interest----- 5300.00

Part I 7.00% per annum ---x
Part II 8.00% per annum ---y
Total investment
x + 1 y= 70000 -------------1
Interest on both investments
7.00% x + 8.00% y= 5300
Multiply by 100
7 x + 8 y= 530000.00 --------2
Multiply (1) by -7
we get
-7 x -7 y= -490000.00
Add this to (2)
0 x 1 y= 40000
divide by 1
y = 40000
Part I 7.00% $ 30000
Part II 8.00% $ 40000

CHECK
30000 --------- 7.00% ------- 2100.00
40000 ------------- 8.00% ------- 3200.00
Total -------------------- 5300.00

m.ananth@hotmail.ca