<PRE><B>Question 1200225</B>
&lt;br&gt;
With formal algebra....&lt;br&gt;
x = amount invested at 10%
30000-x = amount at 5%&lt;br&gt;
The total interest was $2500:&lt;br&gt;
.10(x)+.05(30000-x) = 2500&lt;br&gt;
Solve using basic algebra... I leave that to you.&lt;br&gt;
Informally, if a formal algebraic solution is not required....&lt;br&gt;
All $30000 invested at 5% would have returned $1500 interest; all at 10% would have returned $3000 interest.
The actual interest $2500 is 2/3 of the way from $1500 to $3000.
That means 2/3 of the total was invested at the higher rate.&lt;br&gt;
ANSWER: 2/3 of the $30000, or $20000, at 10%; the other $10000 at 5%&lt;br&gt;
CHECK: .10($20000)+.05($10000) = $2000+$500 = $2500&lt;br&gt;
</PRE>