SOLUTION: Isabel invested her savings in two investment funds. The $6000 that she invested in Fund A returned a 4% profit. The amount that she invested in Fund B returned a 1% pr

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Question 1163062: Isabel invested her savings in two investment funds. The
$6000
that she invested in Fund A returned a
4%
profit. The amount that she invested in Fund B returned a
1%
profit. How much did she invest in Fund B, if both funds together returned a
2%
profit?
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


A formal algebraic setup for solving the problem....

x = amount at 4%
6000-x = amount at 1%

The average return on the $6000 was 2%:

.04%28x%29%2B.01%286000-x%29+=+.02%286000%29

Solve using basic algebra (I leave that to you)....

A quick and easy solution method, using logical reasoning and a bit of mental arithmetic....

The average return of 2% is "twice as close to 1% as it is to 4%". That means the amount invested at 1% was twice the amount invested at 4%.

ANSWER: $4000 at 1%; $2000 at 4%

CHECK:
.01(4000)+.04(2000) = 40+80 = 120
.02(6000) = 120

Or here is a variation of this easy method, thinking a bit differently....

The average return of 2% is 1/3 of the way from 1% to 4% (picture the three percentages on a number line). Therefore, 1/3 of the total was invested at 4%.

ANSWER: 1/3 of the total $6000, or $2000, at 4%; the rest at 1%.