SOLUTION: invested 10000$ for 1 year party at 7% and part 6.25% if she earned a total interest of 656.50$ how much was invested at each rate?

Question 899336: invested 10000$ for 1 year party at 7% and part 6.25% if she earned a total interest of 656.50$ how much was invested at each rate?
Answer by mananth(16946) (Show Source): You can put this solution on YOUR website!
Part I 7.00% per annum ------------- Amount invested =x
Part II 6.25% per annum ------------ Amount invested = y
10000
Interest----- 656.50

Part I 7.00% per annum ---x
Part II 6.25% per annum ---y
Total investment
x + 1 y= 10000 -------------1
Interest on both investments
7.00% x + 6.25% y= 656.5
Multiply by 100
7 x + 6.25 y= 65650.00 --------2
Multiply (1) by -7
we get
-7 x -7 y= -70000.00
Add this to (2)
0 x -0.75 y= -4350
divide by -0.75
y = 5800
Part I 7.00% $ 4200
Part II 6.25% $ 5800

CHECK
4200 --------- 7.00% ------- 294.00
5800 ------------- 6.25% ------- 362.50
Total -------------------- 656.50

m.ananth@hotmail.ca

RELATED QUESTIONS
Marissa invested $7000 for 1 year. Part was invested at 4% simple interest and part... (answered by checkley79)

Aimee calhoun invested $12500 part at 7% simple interest and part at 6% simple interest... (answered by josmiceli,chitra)

Susan invested $12,350, part at 7% simple interest and part at 6% simple interest for a... (answered by richwmiller)

Ethan invested $19,000 for 1 year, part at 11% simple interest and part at 13% simple... (answered by ikleyn,mananth,Edwin McCravy,greenestamps)

.need equation so I can solve the problem math problem ?Arlene invested $29,000 for... (answered by ReadingBoosters)

You invested $7000 in two accounts paying 7% and 6% annual interest, respectively. If... (answered by mananth)

You invested $7000 in two accounts paying 6% and 7% annual interest, respectively. If the (answered by rothauserc)

Mary invested 10000 part at 4% and part at 5% for 1 year. How much was invested in each... (answered by Boreal)

Mary invested 10000 part at 4% and part at 5% for 1 year. How much was invested in each... (answered by richwmiller)