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Problem of the Day #336: Boating across the River February 18, 2012

Posted by Alex in : potd , trackback

$999$ people, numbered $2$ to $1000$, are all on one side of a river and wish to reach the other side. There is a single boat with infinite capacity, but a group of people can only ride the boat together if every pair of people on the boat have numbers that are relatively prime. How many back-and-forth trips are needed to transport every person across the river?

You may use a computer program.


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