<PRE><B>Question 61075</B>
A total of $1150 was invested, part of it at 12% and part at 11%. The total yield was $133.75.  How much was invested at each rate?

Let A = amount invested at 12%.
Let B = amount invested at 11%.

A total of $1150 was invested so {{{A+B=1150}}}.
The total yield = {{{.12A+.11B=133.75}}}.
Since {{{A+B=1150}}}, {{{B=1150-A}}}.
Substitute {{{B=1150-A}}} into {{{.12A+.11B=133.75}}}
and you get {{{.12A+.11(1150-A)=133.75}}}.
Simplify and you get {{{.12A+126.5-.11A=133.75}}}.
Simplify more and you get {{{.01A+126.5=133.75}}}.
Subtract 126.5 from both sides and you get {{{.01A=7.25}}} or {{{A=725}}}.
So, $725 was invested at 12% A total of $1150 was invested so the balance, $425, was invested at 11%.

To verify, plug the values of A and B into {{{.12A+.11B=133.75}}}.
{{{.12(725)+.11(425) = 87+46.75 = 133.75}}}.</PRE>