SOLUTION: Investing. John invests twice as much money at 6% as he does 5%. If his investments earn a total of $680 in 1 year, how much does he have invested at each rate?

Question 54319: Investing. John invests twice as much money at 6% as he does 5%. If his investments earn a total of $680 in 1 year, how much does he have invested at each rate?
Found 2 solutions by jainenderkapoor, stanbon:
Answer by jainenderkapoor(61) (Show Source): You can put this solution on YOUR website!

Let us suppose that amount invested at 5% be = $100
then amount invested at 6% = $200
Now $100 invested at 5% for 1 year gives --- I = P*R*T/100
I = 100*5*1/100 = 5
AND $200 invested at 6% for 1 year gives
I = 200*6*1/100 = 12
Total Earning = 5 + 12 = 17

If total earning is 17 amount invested = 100
If total earning is 680 amount invested = 100 * 680/17 = 100*40 = $4000
And the amount invested at 5% is $4000 and at 6% is $8000

I hope that the solution is clear to you.
If you have any doubt you are welcome to contact me.
I am also available for online tutoring in math at very reasonable rates.
My mail id is jainenderkapoor@gmail.com
Jainender Kapoor

Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
John invests twice as much money at 6% as he does 5%. If his investments earn a total of $680 in 1 year, how much does he have invested at each rate?
---------
Let amount invested at 5% be "x".
Interest on that money is 0.05x dollars
----------
Amount invested at 6% is "2x".
Interest on that money is 0.06(2x)=0.12x
----------
EQUATION:
0.05x + 0.12x = 680
0.17x=680
x=$4000 (Amount invested at 5%)
2x=$8000 (Amount invested at 6%)
Cheers,
Stan H.

RELATED QUESTIONS
John invests twice as much money at 6% as he does at 5%. If his investments earn a total (answered by nerdybill)
Could you help me find out how much John has invested? John invests twice as much money... (answered by stanbon)
john has twice as much money invested in stocks as in bonds. Stocks earn 8% interest each (answered by mananth)
Sally invests twice as much in Stock Ventures 1 at 8% interest as in Stock Ventures 2 at... (answered by mananth)
bob has twice as much money invested in a 5% account as he does invested at a 4% account. (answered by Boreal)
A broker has twice as much money invested at 8% as he has invested a 6.5% if his total... (answered by addingup)
susan invests twice as much money at 7.5% as she does at 6%. If her total interest after (answered by mananth)
Nico is saving for college. He invests some money at 9% and $1500 less than that amount... (answered by solver91311)
John has $10,220 to invest. He invests part of his money in a CD at 5% interest and the... (answered by checkley77)