<PRE><B>Question 283771</B>
10000 dollars invested at 6% and 11%, one year.  
Total interest was 900 dollars the year.
How much invested at 11%?


P=10000
L=0.06
H=0.11
R=900
y= variable, how much at 11%
P-y = how much at 6%


Accounting for the one year earned interest
{{{highlight_green(L(P-y)+Hy=R)}}}


{{{LP-Ly+Hy=R}}}
{{{(H-L)y+LP=R}}}
{{{(H-L)y=R-LP}}}

{{{highlight(y=(R-LP)/(H-L))}}}


Substituting the values
{{{y=(900-(0.06)(10000))/(0.11-0.06)}}}

{{{y=300/0.05}}}

{{{highlight(y=6000)}}}</PRE>