21-110: Problem Solving in Recreational Mathematics
Homework assignment 8 solutions
Problem 1. A loop is an edge that joins a vertex to itself. Multiple edges are two or more edges
between the same pair of vertices. (See the picture below.) A simple graph
21-110: Problem Solving in Recreational Mathematics
Homework assignment 7
Assigned Monday, April 5, 2010. Due Wednesday, April 14, 2010.
Work at least FOUR of the following problems, at least one of which must be from Part B. All
problems are of equal wei
21-110: Problem Solving in Recreational Mathematics
Homework assignment 7 solutions
Problem 1. An urn contains ve red balls and three yellow balls. Two balls are drawn from the
urn at random, without replacement.
(a) In this scenario, what is the experime
21-110: Problem Solving in Recreational Mathematics
Homework assignment 5 solutions
Problem 1. Make an addition table and a multiplication table for the integers modulo 7 (in other
words, for remainders after division by 7).
Solution. There are only seven
21-110: Problem Solving in Recreational Mathematics
Homework assignment 6
Assigned Friday, March 26, 2010. Due Monday, April 5, 2010.
Work at least FOUR of the following problems, at least one of which must be from Part B. All
problems are of equal weight
21-110: Problem Solving in Recreational Mathematics
Homework assignment 4 solutions
Problem 1. Recall that n!, read n factorial, is the number n (n 1) (n 2) 3 2 1.
For example, 5! = 5 4 3 2 1 = 120. The number 110! ends with a bunch of zeroes. How
many?
S
21-110: Problem Solving in Recreational Mathematics
Homework assignment 6 solutions
Problem 1. Normal Pennsylvania license plates have three capital letters followed by four numerical
digits. Assuming there are no other restrictions, how many possible lic
21-110: Problem Solving in Recreational Mathematics
Homework assignment 4
Assigned Friday, February 19, 2010. Due Friday, February 26, 2010.
Work at least FOUR of the following problems. All problems are of equal weight. If you submit
solutions for more t
21-110: Problem Solving in Recreational Mathematics
Homework assignment 5
Assigned Monday, March 15, 2010. Due Wednesday, March 24, 2010.
Work at least FOUR of the following problems, at least one of which must be from Part B. All
problems are of equal we
21-110: Problem Solving in Recreational Mathematics
Homework assignment 2 solutions
Problem 1. Suppose you have one copy of each free hexomino. Prove that it is impossible to
arrange them into a rectangle.
Solution. There are 35 free hexominoes. Each hexo
21-110: Problem Solving in Recreational Mathematics
Homework assignment 3 solutions
Problem 1. (A Swimmer and a Hat, from The Moscow Puzzles by Boris A. Kordemsky, edited
by Martin Gardner.) A boat is being carried away by a current. A man jumps out and s
21-110: Problem Solving in Recreational Mathematics
Homework assignment 3
Assigned Friday, February 5, 2010. Due Friday, February 12, 2010.
Work at least FOUR of the following problems. All problems are of equal weight. If you submit
solutions for more th
21-110: Problem Solving in Recreational Mathematics
Homework assignment 1 solutions
Problem 1. Find my oce. Sign your name on the sheet posted outside my oce door.
Solution. My oce is in the Physical Plant Building (PPB), room 342. One way to get there is
21-110: Problem Solving in Recreational Mathematics
Homework assignment 2
Assigned Monday, January 25, 2010. Due Monday, February 1, 2010.
Work at least FOUR of the following problems. All problems are of equal weight. If you submit
solutions for more tha
21-110: Problem Solving in Recreational Mathematics
Homework assignment 1
Assigned Wednesday, January 13, 2010. Due Wednesday, January 20, 2010.
Work at least FOUR of the following problems. All problems are of equal weight. If you submit
solutions for mo