Mathematics Problem Of the Week

Fall 2005

POW #13

SLUdoku

 

A traditional Sudoku puzzle consists of a 9x9 grid where the integers 1 to 9 must appear exactly once in each row, once in each column and once in each of the nine disjoint 3x3 subsquares.  To solve a Sudoku puzzle (such as the one on the left below), one must find the values in each empty cell, given some of the values in the other cells.

1

 

2

 

 

 

 

3

 

 

4

 

 

 

1

5

 

 

5

6

 

 

 

7

8

 

 

9

 

 

1

3

 

 

 

6

7

 

 

 

2

 

 

 

8

4

 

 

 

5

8

 

 

1

 

 

5

4

 

 

 

7

3

 

 

3

8

 

 

 

2

 

 

1

 

 

 

 

9

 

5

 
 

1

 

 

 

 

2

1

 

2

 

3

 

 

 

 

4

 

 

 
 
 

 

 

 

 

 

 

 

 

 


A SLUdoku (Sudoku Lite) puzzle is an easier version played on a 4x4 grid with the digits 1, 2, 3, and 4 appearing in each row, column and the four main subsquares.

 

(a) Solve both the 9x9 Sudoku and 4x4 SLUdoku puzzles shown above.

 

(b) In general, how many different rearrangements are possible for a 4x4 SLUdoku grid?  Justify your answer.

 

Last POW for the Semester!             Due Friday, December 2nd Noon

Solutions should be submitted to Dr. R. Lock's mailbox in the Math office or sent via e-mail to rlock@stlawu.edu.