Question 779591
 A total of $3700 was invested, part of it at 6% interest and the remainder at 11%. 
If the total yearly interest amounted to $330, how much was invested at each rate? 
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 A total of $T was invested, part of it at c% interest and the remainder at g%. 
If the total yearly interest amounted to $n, how much was invested at each rate? 
(All values are as variables.)
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invested v at g% and therefore invested T-g at c%.

The amounts of earned interests were {{{(c/100)(T-v)}}} and {{{(g/100)v}}}.
Their sum n, was given, so {{{(c/100)(T-v)+(g/100)v=n}}}.

Solve the equation for v.

{{{c(T-v)+gv=100n}}}

{{{cT-cv+gv=100n}}}

{{{gv-cv=100n-cT}}}

{{{highlight(v=(100n-cT)/(g-c))}}}, for ALL such examples which fit this same exact format.