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%TCIDATA{Created=Wednesday, September 21, 2005 19:23:38}
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\begin{document}


\begin{center}
\bigskip {\Large Puzzle 11}
\end{center}

\bigskip

\bigskip A bus makes a roundtrip between towns A and B. From A to B, the bus
completes the trip with an average speed of $60$ $\dfrac{\text{mi}}{\text{hr}%
}$. From B to A, it travels with an average velocity of $40$ $\dfrac{\text{mi%
}}{\text{hr}}$. What is the average speed of the bus for the entire
roundtrip? (Hint: it is NOT the average of $40$ and $60$.)

\bigskip

\bigskip

\end{document}