Question 1158944
<br>
Here is a non-algebraic alternative for solving "mixture" problems like this.<br>
$13,500 all at 9% would yield $1215 interest.
$13,500 all at 3% would yield $1755 interest.
The actual interest was $1635.<br>
On a number line (if you want to think of it that way), 1635 is 420/540 = 7/9 of the way from 1215 to 1755.<br>
Therefore, 7/9 of the total was invested at 13% (and the other 2/9 of it at 9%).<br>
2/9 of $13,500 is $3000; 7/9 is $10,500.<br>
ANSWER: $10,500 at 13%; $3000 at 9%.<br>
CHECK:
.13(10,500)+.09(3000) = 1365+270 = 1635<br>