<PRE><B>Question 1196839</B>
&lt;br&gt;
(1) A typical formal algebraic setup for solving the problem....&lt;br&gt;
x = amount invested at 5%
50000-x = amount invested at 10%&lt;br&gt;
The total earnings are $4000:&lt;br&gt;
{{{.05(x)+.10(50000-x)=4000}}}&lt;br&gt;
Basic algebra from there; I&#39;ll let you finish.&lt;br&gt;
(2) An informal solution (quick and easy, if a formal algebraic solution is not required)....&lt;br&gt;
$4000 earnings on an investment of $50,000 is a rate of 8%.
8% is 3/5 of the way from 5% to 10% (view the three percentages on a number line if it helps....)
That means 3/5 of the total should be invested at the higher rate.&lt;br&gt;
ANSWER: 3/5 of $50,000, or $30,000, at 10%; the other $20,000 at 5%&lt;br&gt;
CHECK: .10(30000)+.05(20000) = 3000+1000 = 4000&lt;br&gt;
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