MCS Puzzle Contest

Hello All,

 

We have been sending out a weekly teaser problem in our announcementsย of the Pizza & Problem Solving sessions thatย the MCS Department hasย been hosting on Tuesday afternoons. We would like to make this aย little more official and turn these into a problem solving contest.ย The plan is to post a problem (or two) maybe not every week, but everyย two weeks. We would like to encourage you to work on these andย actually submit written up solutions to us. There will be prizes forย the best solutions.ย ย Here are the first two problems, one for math majors, the other forย non-math majors. Whether you are a math major or not, you are welcome
to work on and submit a solution to either or both problems, but theย problems intended for math majors are likely to be more challenging
and/or technical. Solutions are due by May 10 and can be submitted byย e-mail or on paper (typed or handwritten, as you wish) to either Dr.
Siehler or to Dr Tuba.

Problem for math major types:

Let x and y be positive integers such that x+y=2018. Suppose that weย have an x by y chessboard and each square has a pawn on it (the colorย of the pawn is irrelevant). When the clock strikes midnight, all ofย the pawns come alive and each one simultaneously moves to an adjacentย square (but not diagonally) and then becomes a lifeless chess pieceย again. Upon the completion of all these moves, it is still true thatย each square of the board has exactly one pawn on it. For which valuesย of the pair (x,y) is this possible?

Problem for non-math major types:

The four cards shown below have an interesting property: ย the upperย numbers run from one to four, and — this is the interesting part —ย each card’s lower number tells how many times the upper number occursย anywhere in the entire set of cards. `1′ occurs 3 times; `2′ occurs 1ย time; `3′ occurs 3 times; `4′ occurs 1 time. ย  mazing! Your problem:ย Construct a set of ten cards with upper numbers 1–10 and the sameย “self-counting” property.