Book:Angela Dunn/Mathematical Bafflers/Revised Edition

Contents

 * Preface to the Dover Edition


 * 1. SAY IT WITH LETTERS
 * Algebraic Amusements


 * 2. AXIOMS, ANGLES, AND ARCS
 * Geometric Exercises


 * 3. SOLVING IN INTEGERS
 * Diophantine Diversions


 * 4. THE DATA SEEKERS
 * Problems in Logic and Deduction


 * 5. MINDING YOUR P's AND Q's
 * Proability Posers


 * 6. NOW YOU SEE IT
 * Insight Puzzles


 * 7. PERMUTATIONS, PARTITIONS, AND PUZZLES
 * Assorted Number Theory Problems



Four Fours: $13$
Four Fours: Solution

Source work progress
* : $1$. Say it with Letters: Algebraic Amusements: Four Fours