Question 1185811
<br>
A standard "mixture" problem....<br>
First a standard setup for solving the problem using algebra.<br>
x dollars at 6%, plus (14000-x) dollars at 16%, yields $1500 interest.<br>
{{{.06(x)+.16(14000-x)=1500}}}<br>
Solve using basic algebra, although the numbers are a bit messy.<br>
And now a quick and easy way to solve any 2-part mixture problem like this, if a formal algebraic solution is not required and your mental math skills are good.<br>
$14,000 all invested at 6% would yield $840 interest; all at 16% would yield $2240 interest; the actual interest was $1500.<br>
Picture the three interest amounts -- 840, 1500, and 2240 -- on a number line and observe/calculate that 1500 is 660/1400 of the way from 840 to 2240.  That means 660/1400 of the total was loaned at the higher rate.<br>
{{{14000(660/1400)=6600}}}<br>
ANSWER: $6600 was loaned at 16%; the other $7400 at 6%.<br>
CHECK: .16(6600)+.06(7400)=1056+444=1500<br>