Sunday Puzzle

It's Sunday again, and you know what that means—time for me to rip off the puzzle segment from NPR's Weekend Edition Sunday!

Mustachioed enigmatologist

extraordinaire, Will Shortz

If you're a newcomer, each week on Weekend Edition Sunday, Will Shortz (the hardcore crossword puzzlers' almighty God) comes on the radio to do three things: share the solution to the previous week's puzzle, invite a winner who entered the correct answer to play another puzzle (usually word-related) on the air for word-nerdy prizes, and present everyone with the next week's puzzle (answers due in by Thursday afternoon via the WES website if you want a chance to play on the air).

Note: I never post the solutions on this blog…at least not before the submission deadline. I see lots of keyword traffic coming from people looking for the answers, which is at best impatient, and at worst, cheating. For shame.

Now without further ado, here's this week's new puzzle:

This Hat Rack Puzzle by Sam Lloyd was published 100 years ago in Woman's Home Companion: A hat room contains a wall with 49 pegs, arranged in a 7-by-7 square. The hat clerk has 20 hats that are to be hung on 20 different pegs. How many lines, containing four hats in a straight line, is it possible to produce? A line can go in any direction: horizontally, vertically or obliquely. To explain your answer, number the pegs in order, from 1 in the upper left corner to 49 in the lower right corner; list which pegs you put the 20 hats on, and give the total number of lines containing four hats in a row.

Click here to see the original puzzle posting, check the answer to last week's challenge, listen to the segment, or find the link to enter your answer.