Question 1122870
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<pre>

Let x = amount she invested in Fund B, in dollars (the value under the question).


The interest from Fund A  is 0.1*4000  dollars.

The interest from Fund B  is 0.03*x   dollars.

Total interest is  0.05*(4000+x).



Your equation is


    <U>interest</U> + <U>interest</U>      = <U>total interest</U>,   or

    0.1*4000  + 0.03*x       = 0.05*(4000+x)   dollars.


    400       + 0.03x        = 200 + 0.05x

    400 - 200 = 0.05x - 0.03x

    200 = 0.02x  ====>  x = {{{200/0.02}}} = 10000.


<U>Answer</U>.  $10000 were invested in Fund B.


<U>Check</U>.   0.1*4000 + 0.03*10000 = 700 dollars.   

         0.05*(4000+10000) = 700 dollars.    ! Correct !
</pre>

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It is a typical and standard problem on investment.


To see many other similar solved problems on investment, &nbsp;look into the lesson

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/coordinate/lessons/Using-systems-of-equations-to-solve-problems-on-investment.lesson>Using systems of equations to solve problems on investment</A>

in this site.


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


Also, &nbsp;you have this free of charge online textbook in ALGEBRA-I in this site

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson>ALGEBRA-I - YOUR ONLINE TEXTBOOK</A>.


The referred lesson is the part of this online textbook under the topic &nbsp;"<U>Systems of two linear equations in two unknowns</U>".



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.