SOLUTION: Charlie invested his savings in two investment funds. The $4000 that he invested in Fund A returned a 2% profit. The amount that he invested in Fund B returned a 5% pro

Algebra ->  Linear-equations -> SOLUTION: Charlie invested his savings in two investment funds. The $4000 that he invested in Fund A returned a 2% profit. The amount that he invested in Fund B returned a 5% pro      Log On


   



Question 1103832: Charlie invested his savings in two investment funds. The
$4000
that he invested in Fund A returned a
2%
profit. The amount that he invested in Fund B returned a
5%
profit. How much did he invest in Fund B, if both funds together returned a
3%
profit?

Found 3 solutions by greenestamps, ikleyn, richwmiller:
Answer by greenestamps(13203) About Me  (Show Source):
You can put this solution on YOUR website!


NOTE: I misread the problem, thinking that the $4000 was the total amount invested.

Skip down to the ================= to see the revised solution.

Here, first, is the quick way to get the answer to a problem like this. We can look at the slow, formal algebraic method later.

The 3% average return is twice as close to 2% as it is to 5%. That means twice as much was invested at 2% as at 5%.

That means the $4000 was invested with 2/3 of it at 2% and 1/3 of it at 5%.

1/3 of $4000 is $1333.33 (which indicates "bad" numbers are used for this problem....)
2/3 of $4000 is $2666.67

So the amount he invested in Fund B was $1333.33.


Now the standard algebraic solution method....

"The return for x amount in Fund B at 5%, plus the return for the rest (4000-x) in Fund A at 2%, yielded an average return of 3% on the total investment".
Translated into an algebraic equation,
.05%28x%29%2B.02%284000-x%29+=+.03%284000%29 [note the form for each term on both sides of the equation is the same: (interest rate)*(amount)]
5%28x%29%2B2%284000-x%29+=+3%284000%29 [simplify the calculation by getting rid of the decimals]
5x%2B8000-2x+=+12000
3x+=+4000
x+=+1333.33

The amount invested in Fund B at 5% was $1333.33.

========================================================================
Here, first, is the quick way to get the answer to a problem like this. We can look at the slow, formal algebraic method later.

The 3% average return is twice as close to 2% as it is to 5%. That means twice as much was invested at 2% as at 5%.

Since twice as much was invested in Fund A as in Fund B, the amount he invested in Fund B was $2000.


Now the standard algebraic solution method....

"The return for x amount in Fund B at 5%, plus the return for the 4000 in Fund A at 2%, yielded an average return of 3% on the total investment".
Translated into an algebraic equation,
.05%28x%29%2B.02%284000%29+=+.03%284000%2Bx%29 [note the form for each term on both sides of the equation is the same: (interest rate)*(amount)]
5%28x%29%2B2%284000%29+=+3%284000%2Bx%29 [simplify the calculation by getting rid of the decimals]
5x%2B8000+=+12000%2B3x
2x+=+4000
x+=+2000

The amount invested in Fund B at 5% was $2000.


Answer by ikleyn(52817) About Me  (Show Source):
You can put this solution on YOUR website!
.
Charlie invested his savings in two investment funds.
The $4000 that he invested in Fund A returned a 2% profit.
The amount that he invested in Fund B returned a 5% profit.
How much did he invest in Fund B, if both funds together returned a 3% profit?
~~~~~~~~~~~~~~~~~~~~~~~~~~~

interest  + interest = interest

0.02*4000 + 0.05*x   = 0.03*(4000+x)

80        + 0.05x    = 120 + 0.03x

0.05x - 0.03x = 120 - 80

0.02x = 40  ====>  x = 40%2F0.02 = 4000%2F2 = 2000.


Answer.  $2000 was invested in Fund B.


Check.  0.02*4000 + 0.05*2000 = 180  dollars;

        0.03*(4000 + 2000) = 180 dollars.    ! Correct !

-------------------
To see other similar problems on investment solved, look into the lesson
    - Using systems of equations to solve problems on investment
in this site.


Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
We have 4000 dollars of 2% investment.
Using the method of alligation.
2         2        4000 dollars of 2% investment
      3            6000 dollars of 3% investment
5         1 1/2*4000=2000 dollars of 5% investment
           3

1= 3 - 2
2= 5 - 3
2000= 4000/(2/1) dollars of 5% investment to add to your 4000 dollars of 2% investment.
6000= (4000+2000) dollars of the final 3% investment.
check
0.05 * 2000 + 0.02 * 4000 = 0.03*(4000+2000)
100.0 + 80.0 = 0.03*(6000)
180.0 = 180.0
ok