1953 AHSME Problems/Problem 17
Problem
A man has part of \$
invested at
% and the rest at
%. If his annual return on each investment is the same, the average rate of interest which he realizes of the \$4500 is:
Solution
You are trying to find
, where
is the principle for one investment. To find
, solve
.
will come out to be
. Then, plug in x into the first equation,
, to get
. Finally, convert that to a percentage and you get
.