Fifth Friday of the Month

When they checked their schedules, several busy women found the only time they could schedule for their book club was the fifth Friday of the month.  Not every month has a fifth Friday, but they weren't concerned, since they'd need the extra time to read the books anyway.

  1. On average, how often will the book club meet each year?

  2. What is the shortest time between meetings?

  3. What is the longest time between meetings?

Source: Original.


Solutions were received from Joseph DeVincentis, David Bachtel, Jeremy Galvagni, Kirk Bresniker, Raśl Mora Pastor, Dan Chirica, Michael J. Winckler, Bernie Erickson, Ramkumar Ganesan, and David Madfes.
  1. On average, they will meet 4.14 times per year.

  2. The shortest time between meetings is 9 weeks, as between September 30 and December 30, 2005.

  3. The longest time between meetings is 17 weeks, as between December 31, 2004 and April 29, 2005.


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