Question 1169113
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First, a setup using a typical formal algebraic method....<br>
"x amount at 4%, plus $24000-x amount at 3%, equals $800":<br>
{{{x(.04)+(24000-x)(.03) = 800}}}<br>
Solve using basic algebra; I leave that to you.<br>
Next, a quick and easy informal way to solve any 2-part mixture problem like this, if a formal algebraic solution is not required.<br>
$24,000 all invested at 3% would yield $720 dividend<br>
$24,000 all invested at 4% would yield $960 dividend<br>
The actual dividend, $800, is 1/3 of the way from $720 to $960.  (Picture the three numbers on a number line; from 720 to 960 is a difference of 240, from 720 to 800 is a difference of 80, 80/240 = 1/3.)<br>
That means 1/3 of the total was invested at the higher rate.<br>
ANSWER: 1/3 of $24,000, or $8000 was invested at 4%; the other $16,000 at 3%.<br>
CHECK: .04(8000)+.03(16000) = 320+480 = 800<br>