Question 1144404
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(1) A traditional algebraic solution....<br>
let x be the amount invested at 5%
then 9000-x is the amount invested at 6%<br>
The total interest is 5% of x plus 6% of (9000-x):<br>
{{{.05(x)+.06(9000-x) = 480}}}<br>
Solve using basic algebra....<br>
(2) A solution found by comparing the actual interest to the amounts of interest if the whole $9000 had been invested at one rate of the other....<br>
$9000 all at 5% would yield $450 interest
$9000 all at 6% would yield $540 interest<br>
$480 is 1/3 of the way from $450 to $540 (picture the three numbers 450, 480, and 540 on a number line...)<br>
Therefore, 1/3 of the total was invested at the higher rate.<br>
ANSWER: 1/3 of $9000, or $3000, at 6%; the other $6000 at 5%.<br>
CHECK:
.05(6000)+.06(3000) = 300+180 = 480