Question 1149483
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If an algebraic solution is not required, then compare the amount of work required by this alternative method with that required with the standard algebraic solution shown by the other tutor.<br>
$6000 all at 4% --> $240 interest
$6000 split between 4% and 7% --> $375 interest
$6000 all at 7% --> $420 interest<br>
$375 is 3/4 of the way from $240 to $420.  ($240 to $375 is $135; $240 to $420 is $180; 135/180 = 3/4.  Picture the three numbers on a number line if it helps you see the 3/4.)<br>
That means 3/4 of the investment is at the higher rate.<br>
ANSWER: 3/4 of $6000, or $4500, at 7%; the other $1500 at 4%.<br>
CHECK:
.07(4500)+.04(1500) = 315+60 = 375<br>