Question 190386
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Let <font color=blue> x </font>= amount inv. @ 5%
And, <font color=blue> 2x </font>= amount for 9% (twice that of lower rate 5%)


Then it follows, 
Interest on 5% + Interest on 9% = $920
{{{0.05x+0.09(2x)=920}}}
{{{0.05x+0.18x=920}}}
{{{0.23x=920}}} ----> {{{cross(0.23)x/cross(0.23)=cross(920)4000/cross(0.23)}}}
<font color=blue>x = $4,000.00 </font>, amount for 5%


Also, 2*($4,000) = <font color=blue> $8,000.00 </font>, amount for 9%



Let's check,
{{{0.05(4000)+0.09(8000)=920}}}
{{{200+720=920}}}
{{{920=920}}}


Thank you,
Jojo</font>