Final Problem!! 

11/20/06  

Week #13  Mon. Nov. 20 - Fri. Dec. 1  

Problem 13 (25 points) In a certain competition, a player scores either M or N points at the end of each round, were M and N are given positive integers. The player notices that her cumulative score can take any positive integer value except for those in a finite set P, where |P| =1003.  If 60 is not in P, find M and N. 

  

Copies of this problem (and answers to the old problems) are available from the shelves in front of the Math office, MH 308, or online at http://www.math.sjsu.edu/~jackson.  Solutions to problem #13 should be submitted to the Math office by Fri. Dec. 1 at noon.  Remember that a correct solution should also contain an explanation of the answer.  Make sure that your name, student ID number, and the division you are participating in (undergraduate or graduate or SJMC) are printed legibly at the top of the page.  A correct solution to problem #13 and the final results of the 2006 Problem Solving competition will be posted on Mon. Dec. 4.

11/14/06  

Week #12  Mon. Nov. 13 - Wed. Nov. 22  

Problem 12 (20 points) A rectangle is 'weakly integral' if at least one of its dimensions is an integer. 

a) Suppose a large rectangle is tiled with five weakly integral rectangles as in the figure below.  Show that the large rectangle is also weakly integral. 

 

                               h                      g      

                  

 

                                                                       f

               a

 


                                                           y       

                                                    

               b                                x                    e

 

 


                                    c                       d   

b) Prove or disprove: If a large rectangle can be tiled with a collection of weakly integral rectangles, the large rectangle must be weakly integral. 

Copies of this problem (and answers to the old problems) are available from the shelves in front of the Math office, MH 308, or online at http://www.math.sjsu.edu/~jackson.  Solutions to problem #12 should be submitted to the Math office by Wed. Nov. 22 at noon.  Remember that a correct solution should also contain an explanation of the answer.  Make sure that your name, student ID number, and the division you are participating in (undergraduate or graduate or SJMC) are printed legibly at the top of the page.  A correct solution to problem #12 will be posted on Mon. Nov. 27.

11/06/06  

Week #11  Mon. Nov. 6 - Wed. Nov. 15  

Problem 11 (15 points) Show that there do not exist positive real numbers x, y, and z, which satisfy the following system of equations (where a ^ b represents a to the bth power).  

(x + y + z) ^ x =  6/7

(x + y + z) ^ y = 7/8

(x + y + z) ^ z = 8/9.   

10/30/06  

Week #10  Mon. Nov. 6 - Wed. Nov. 15  

Problem 10 (14 points) Is it possible to inscribe a triangle with angles of 45 degrees, 60 degrees, and 75 degrees in a unit circle (x ^2 + y ^ 2 = 1) so that each vertex of the triangle has rational coordinates?  

10/23/06  

 Week #9  Mon. Oct. 23 - Wed. Nov. 1  

 Problem 9 (13 points) For all positive integers m,n show that [(3m)!(3n)!]/[m!n!(m+n)!(n+m)!] is always an integer.  

10/17/06  

 Week #8  Mon. Oct. 16 - Wed. Oct. 25  

 Problem 8 (12 points) A certain island has x red, y blue, and z yellow chameleons, where x,y,z are positive integers.  Whenever two chameleons that are different colors meet, they can both change their color to the third color.  For which triples (x,y,z) of positive integers could all the chameleons ever end up being the same color.  

10/10/06  

Week #7  Mon. Oct. 9 - Wed. Oct. 18  

Problem 7 (11 points) Let n^4 represent the 4th power of n.  Determine all non-negative integral solutions of (n1, n2, n3, ... , n14), if any, of the Diophantine equation 

(n1)^4 + (n2)^4 + ... + (n14)^4 = 1,599.    

10/03/06  

Week #6  Mon. Oct. 2 – Wed. Oct. 11

Problem 6 (10 points) Does there exist a continuous function 

f: R -> R such that the image of every rational number is irrational and the image of every irrational is rational.    

9/25/06  

Week #5  Mon. Sept. 26 – Wed. Oct. 4

Problem 5 (9 points) If P(x) denotes a polynomial of degree n such that P(k) = k/(k+1) for k = 0, 1, 2, ..., n, determine P(n+1).  

9/18/06  

Week #4  Mon. Sept. 19 – Wed. Sept. 27

Problem 4 (8 points) In a certain town it began snowing before noon and continued snowing at a constant rate until dark.  At noon a crew set out along a highway, clearing the snow from it as they went.  They cleared two miles in the first two hours but only one mile in the next two hours.  If the crew clears equal volumes of snow in equal times, at what time did it begin to snow?  

9/11/06  

Week #3  Tues. Sept. 12 – Wed. Sept. 20

Problem 3 (7 points) Given a set of 1004 integers between 1 and 2006 (inclusive), show that at least one member of the set must divide another member of the set.  

9/5/06

Week #2 Tues. Sept. 5 – Wed. Sept. 13 

Problem 2 (6 points) There is a plane with n > 1 seats, and lined up to board are n passengers, each of whom has an assigned seat. The first passenger, who has amnesia and cannot remember his assigned seat, sits in a random seat. Thereafter, as each person in line boards the plane, they look to see if their assigned seat is available. If it is, they sit in it. If it is not, they sit in a random open seat. What is the probability that the last person to board sits in his/her assigned seat? 

8/15/06

Week #1  Wed. Aug. 23 – Wed. Sept. 6  

Problem 1 (5 points):  The combined ages of Mary and Ann are sixty years, and Mary is twice as old as Ann was when Mary was half as old as Ann will be when Ann is three times as old as Mary was when Mary was three times as old as Ann.  How old is Mary?