Putnam 2009 B1
Source:
December 7, 2009
Putnamfactorialinductionabstract algebravectorlogarithmsstrong induction
Problem Statement
Show that every positive rational number can be written as a quotient of products of factorials of (not necessarily distinct) primes. For example, \frac{10}9\equal{}\frac{2!\cdot 5!}{3!\cdot 3!\cdot 3!}.