SOLUTION: One safe investment pays 10% per year, and a more risky investment pays 18% per year. A woman who has $138,600 to invest would like to have an income of $18,740 per year from her i

Algebra.Com
Question 1142577: One safe investment pays 10% per year, and a more risky investment pays 18% per year. A woman who has $138,600 to invest would like to have an income of $18,740 per year from her investments. How much should she invest at each rate?
Found 2 solutions by ankor@dixie-net.com, ikleyn:
Answer by ankor@dixie-net.com(22740)   (Show Source): You can put this solution on YOUR website!
One safe investment pays 10% per year, and a more risky investment pays 18% per year.
A woman who has $138,600 to invest would like to have an income of $18,740 per year from her investments.
How much should she invest at each rate?
:
Let x = amt invested at 18%
then
(138600-x) = amt invested at 10%
:
.18x + .10(138600-x) = 18740
.18x + 13860 - .10x = 18740
.18x - .10x = 18740 - 13860
.08x = 4880
x = 4880/.08
x = $61,000 invested at 18%
then
138600 - 61000 = $77,600 invested at 10%
:
;
:
Check: find how much return on each investment
.18(61000) = 10980
.10(77600) = 7760
-----------------------
total return: 18740

Answer by ikleyn(52855)   (Show Source): You can put this solution on YOUR website!
.
Let x = the amount invested at 10% and y = the amount invested at 18%.


Then from the condition you have these two equations in two unknowns


        x +     y = 138600  dollars    (1)    (total investment)

    0.10x + 0.18y =  18740  dollars    (2)    (total interest)


Solve the system by the Substitution method.

For it, from equation (1) express x = 138000 - y  and substitute it into equation (2). You will get


    0.10*(138600-y) + 0.18y = 18740


Simplify and express y from the last equation; then calculate


    y =  = 61000.


To find x, substitute the found value of y into equation (1). You will get then


    x = 138600 - 61000 = 77600.


ANSWER.  $77600 was invested at 10%  and  $61000 was invested at 18%.


CHECK.   0.10*77600 + 0.18*61000 = 18740  dollars.    ! Correct !

Solved.

-------------------

It is a typical and standard problem on investment.

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

You will find there different approaches  (using one equation or a system of two equations in two unknowns),  as well as
different methods of solution to the equations  (Substitution,  Elimination).

Also,  you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

The referred lesson is the part of this online textbook under the topic  "Systems of two linear equations in two unknowns".


Save the link to this online textbook together with its description

Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson

to your archive and use it when it is needed.



RELATED QUESTIONS

one safe investment pays 10% per year, a more risky investment pays 18% per year. a woman (answered by ikleyn)
One safe investment pays 10% per year, and a more risky investment pays 15% per year. A... (answered by Boreal)
One safe investment pays 6​% per​ year, and a more risky investment pays 12​% per... (answered by math_tutor2020)
One safe investment pays 7​% per​ year, and a more risky investment pays 14​% per... (answered by Theo,MathLover1,greenestamps)
Beth has saved $4500. She would like to earn $250 per year by investing her money. She... (answered by josmiceli)
A retired couple has $192,000 to invest. A safe investment yields 9.5% per year, but a... (answered by ikleyn)
Nina has a total of $ 2500 to invest. She puts part of it in an investment that pays 6%... (answered by checkley79)
Hi, I'm trying to write an equation to solve this problem and running into difficulty: (answered by josgarithmetic)
A retired couple has $380,000 to invest. They chose one relatively safe investment fund (answered by ikleyn)