Whitewash the chickens and vacuum the cat! Doctor E. returns with more of the exciting puzzle contest, open to any valiant UNI or high-school student. A cash prize of $50 will go to the person or team with the most points at the end of the semester, with prizes of $30 and $20 going to the runners up. Certificates will go to all who perform outstandingly. Turning in the correct solution to this week’s puzzle by 10/28 will earn 2 puzzle-points. Turning in the correct solution along with the names of three people who died in the Crisis on Infinite Earths will earn 3 puzzle-points.

Sally the elf likes to climb stairs. She can climb them one step or two steps at a time. The staircase in front of Santa’s workshop has four steps to it. Every day, when she reports to work, she tries to climb it a different way. Sometimes she goes one step at a time (1-1-1-1), sometimes two steps at a time (2-2), sometimes she goes up one step, then two, then one (1-2-1), sometimes she goes up one, another, then two (1-1-2) and vice versa (2-1-1).

So there are a total of five ways she can climb the steps. This suits her fine, because when she reports to work (9AM, M-F) she can go up a different way every day of the week.

This will all change in 1998, when Microsoft acquires Santa’s workshop. He is going to make the l’il toy factory into a huge manufacturing megaplex. Poor Sally is going to have to climb a flight of FORTY stairs to get to work every day at 8 AM (M-Sa). The one bright point in her newly sad life is that she will have LOTS of ways to climb these stairs.

Your puzzle challenge this week will be to compute how many ways Sally can climb this flight of 40 steps. There are more than 10,000 of them, so listing them is probably not the way to go on this one.

The deadline for sending in solutions has expired.  But feel free to take some time to work on this one, and click here to see the answer.   Alternatively, click here to see the current challenge.

Web Page design: Doug Shaw