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{Math Bite: Proof of an Empirical Observation Made by Amos Oz's Character}
\rm
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\centerline{ {\it Doron ZEILBERGER}\footnote{$^1$}
{\eightrm  \raggedright
Department of Mathematics, Temple University,
Philadelphia, PA 19122, USA. 
{\eighttt zeilberg@math.temple.edu \break
http://www.math.temple.edu/\Tilde zeilberg \quad .
Supported in part by the NSF. Feb 8, 1996.
} 
}}
 
In Amos Oz's latest novel {\it Panther in the Basement} (Hebrew, Keter,
Jerusalem, 1995), Proffie, the book's twelve-and-a-quarter-year-old
precocious hero, makes the following observation regarding the
ratio of his age to that of the age of his twenty-year-old neighbor,
Yardena, on whom he has a crush (p. 127):
 
{\it As the years will increase, the distance between me and her will
decrease (in percentage), but the sad side is that this decreasing gap
will decrease more and more slowly. Like a marathon-runner that got tired.}
 
And indeed, the ratio of their ages, $f(t)=t/(7.75+t)$,
is such that $f'(t)=(7.75)/(7.75+t)^2>0$, but
$f''(t)=(-15.5)/(7.75+t)^3<0$. \halmos
 
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