Puzzle of the Week #5

by Nolan Musslewhite '20

​Solvers of last week’s puzzle (in order):    
      1. Brandon Torng
      2. Maggie Wang
      3. Mr. Rick DuPuy

Answer to and commentary on Puzzle #4:
    Classification: Hard. Note: Edits to the original [unclear] prompt courtesy of Brandon Torng ‘20. Though there are multiple ways to solve the problem, personally I believe the best way is to draw a branching diagram (i.e. Dublin is the origin, with the four possible routes branching off from Dublin to Shannon, Cork, Knock, and Kerry, and then each of the time-possible routes from each of these cities branching off, etc.). Ultimately, using such a branching diagram, it can be found (specifics available by request) that there are two possible routes by which Aer O’Port could begin and end in Dublin while visiting all of the Irish airports. These routes share only one leg; IA 18, from Cork to Dublin at 1750. Hence, Aer O’Plane can make O’Port’s journey impossible by canceling IA 18.

Puzzle #5
Nolan Musslewhite (nmusslewhite@stalbansschool.org)

This week’s puzzle: Logic. Obadiah wants Ezekiel and John to guess his birthday, and gives these possible dates: May 15, May 16, May 19, June 17, June 18, July 14, July 16, August 14, August 15, August 17. Ezekiel knows the correct month, and John knows the correct day. Ezekiel says, "I don't know Obadiah's birthday, and I know John doesn't know." In response, John says, "I didn't know at first, but I now know Obadiah’s birthday." Then, Ezekiel says, "Now I also know!" When is Obadiah's birthday?