Links to past riddles and solutions are from this page. If you know any
good riddles that you think might fit in, you're welcome to send them
to the puzzlemaster at riddles
brand.scso.com.
The puzzlemaster is Michael Brand.
| 128. | October 2017 | Riddle | Solution | Coda |
| 127. | September 2017 | Riddle | Solution | Real Sorting |
| 126. | August 2017 | Riddle | Solution | Open Day Riddle |
| 125. | July 2017 | Riddle | Solution | Two Classics |
| 124. | June 2017 | Riddle | Solution | Real Random Walk |
| 123. | May 2017 | Riddle | Solution | More One-to-one Functions |
| 122. | April 2017 | Riddle | Solution | Soko-2048-ban |
| 121. | March 2017 | Riddle | Solution | Ten Years of UyHiP |
| 120. | February 2017 | Riddle | Solution | Sublinear Primes |
| 119. | January 2017 | Riddle | Solution | Linear Primes |
| 118. | December 2016 | Riddle | Solution | Return to Prepostria |
| 117. | November 2016 | Riddle | Solution | Leibniz 300 |
| 116. | October 2016 | Riddle | Solution | Concave Quadrilaterals |
| 115. | September 2016 | Riddle | Solution | Random Errors |
| 114. | August 2016 | Riddle | Solution | Mutual Acquaintances |
| 113. | July 2016 | Riddle | Solution | Tower of Hats |
| 112. | June 2016 | Riddle | Solution | Three Stone Paths |
| 111. | May 2016 | Riddle | Solution | Means |
| 110. | April 2016 | Riddle | Solution | Which Number? |
| 109. | March 2016 | Riddle | Solution | MFCIS Margin |
| 108. | February 2016 | Riddle | Solution | Planes on a Hypercube |
| 107. | January 2016 | Riddle | Solution | Latin |
| 106. | December 2015 | Riddle | Solution | Common Subgraphs |
| 105. | November 2015 | Riddle | Solution | Unbiased Estimation |
| 104. | October 2015 | Riddle | Solution | Universal Probabilities |
| 103. | September 2015 | Riddle | Solution | Coins on a Board |
| 102. | August 2015 | Riddle | Solution | 3xn+1 |
| 101. | July 2015 | Riddle | Solution | Centenary |
| 100. | June 2015 | Riddle | Solution | Odds and Evens |
| 99. | May 2015 | Riddle | Solution | Expanding Sets |
| 98. | April 2015 | Riddle | Solution | Even More Quadrilateral Inequalities |
| 97. | March 2015 | Riddle | Solution | More Quadrilateral Inequalities |
| 96. | February 2015 | Riddle | Solution | Quadrilateral Inequality |
| 95. | January 2015 | Riddle | Solution | Surjection/Injection |
| 94. | December 2014 | Riddle | Solution | Casinos |
| 93. | November 2014 | Riddle | Solution | One Coin |
| 92. | October 2014 | Riddle | Solution | Two Coins |
| 91. | September 2014 | Riddle | Solution | Even More Jigsaw Puzzles |
| 90. | August 2014 | Riddle | Solution | Balancing Rounded Irrationals |
| 89. | July 2014 | Riddle | Solution | More Jigsaw Puzzles |
| 88. | June 2014 | Riddle | Solution | The Missing Piece |
| 87. | May 2014 | Riddle | Solution | Fun with Random Bits |
| 86. | April 2014 | Riddle | Solution | 2048 |
| 85. | March 2014 | Riddle | Solution | Squares and Rectangles |
| 84. | February 2014 | Riddle | Solution | On the Shoulders of Giants |
| 83. | January 2014 | Riddle | Solution | Table-turning Genie |
| 82. | December 2013 | Riddle | Solution | Christmas at MegaCorp |
| 81. | November 2013 | Riddle | Solution | Parenthesis Values |
| 80. | October 2013 | Riddle | Solution | King Tours |
| 79. | September 2013 | Riddle | Solution | Rook Tours |
| 78. | August 2013 | Riddle | Solution | Fun with L2 |
| 77. | July 2013 | Riddle | Solution | PSP |
| 76. | June 2013 | Riddle | Solution | Horner's Dilemma |
| 75. | May 2013 | Riddle | Solution | Coin Verification |
| 74. | April 2013 | Riddle | Solution | k-resistance |
| 73. | March 2013 | Riddle | Solution | A185028 |
| 72. | February 2013 | Riddle | Solution | More Takeaways |
| 71. | January 2013 | Riddle | Solution | Take Away |
| 70. | December 2012 | Riddle | Solution | A Problem with Neighbors |
| 69. | November 2012 | Riddle | Solution | Fun with Normal Distributions |
| 68. | October 2012 | Riddle | Solution | Rectangling Another Rectangle |
| 67. | September 2012 | Riddle | Solution | Hydra Games |
| 66. | August 2012 | Riddle | Solution | Euler Numbers |
| 65. | July 2012 | Riddle | Solution | Stepping Contest |
| 64. | June 2012 | Riddle | Solution | Lucky Numbers |
| 63. | May 2012 | Riddle | Solution | Two Polygons |
| 62. | April 2012 | Riddle | Solution | Natural Partitions |
| 61. | March 2012 | Riddle | Solution | Rectangling the Rectangle |
| 60. | February 2012 | Riddle | Solution | Space-efficient Exponentiation |
| 59. | January 2012 | Riddle | Solution | From A to B |
| 58. | December 2011 | Riddle | Solution | Post-office Tetrahedra |
| 57. | November 2011 | Riddle | Solution | Post-office Volumes |
| 56. | October 2011 | Riddle | Solution | Post-office Dilemma |
| 55. | September 2011 | Riddle | Solution | Gladiators |
| 54. | August 2011 | Riddle | Solution | Equinox Counting |
| 53. | July 2011 | Riddle | Solution | Bananas |
| 52. | June 2011 | Riddle | Solution | Improved FFT |
| 51. | May 2011 | Riddle | Solution | Fun with Trigonometry |
| 50. | April 2011 | Riddle | Solution | Cyclone Frogs |
| 49. | March 2011 | Riddle | Solution | Lights-Out |
| 48. | February 2011 | Riddle | Solution | Tea or Coffee |
| 47. | January 2011 | Riddle | Solution | Prepostria |
| 46. | December 2010 | Riddle | Solution | 2-bend Graph Embeddings |
| 45. | November 2010 | Riddle | Solution | DNFs and Symmetric Functions |
| 44. | October 2010 | Riddle | Solution | Abraham and Benjamin |
| 43. | September 2010 | Riddle | Solution | Gloved Prisoners |
| 42. | August 2010 | Riddle | Solution | Tetrahedron Crossing |
| 41. | July 2010 | Riddle | Solution | A Tribute to Gardner |
| 40. | June 2010 | Riddle | Solution | Cyclic Permutations |
| 39. | May 2010 | Riddle | Solution | Segment-preserving Mappings |
| 38. | April 2010 | Riddle | Solution | Self Assembled Numbers |
| 37. | March 2010 | Riddle | Solution | Taylor Series |
| 36. | February 2010 | Riddle | Solution | Laura Sort |
| 35. | January 2010 | Riddle | Solution | Encyclopedia Sort |
| 34. | December 2009 | Riddle | Solution | Dividing the Naturals |
| 33. | November 2009 | Riddle | Solution | Polynomial Solutions |
| 32. | October 2009 | Riddle | Solution | Local Minima |
| 31. | September 2009 | Riddle | Solution | Pythagorean Triplets |
| 30. | August 2009 | Riddle | Solution | Boolean Functions |
| 29. | July 2009 | Riddle | Solution | Steiner Systems with k=3 |
| 28. | June 2009 | Riddle | Solution | Counting Solutions to x2+y2 |
| 27. | May 2009 | Riddle | Solution | Perfect Numbers |
| 26. | April 2009 | Riddle | Solution | Counting Triangles |
| 25. | March 2009 | Riddle | Solution | Fun with Uniform Distributions |
| 24. | February 2009 | Riddle | Solution | O(1) Factorial |
| 23. | January 2009 | Riddle | Solution | O(1) Sorting |
| 22. | December 2008 | Riddle | Solution | O(n) Sorting |
| 21. | November 2008 | Riddle | Solution | Combinations of 1s |
| 20. | October 2008 | Riddle | Solution |  |
| 19. | September 2008 | Riddle | Solution | Permutation Reversal |
| 18. | August 2008 | Riddle | Solution | Trisecting the Square |
| 17. | July 2008 | Riddle | Solution | Sudoku |
| 16. | June 2008 | Riddle | Solution | Knights of the Round Table |
| 15. | May 2008 | Riddle | Solution | Permutation Partial Sums |
| 14. | April 2008 | Riddle | Solution | Partial Harmonic Series |
| 13. | March 2008 | Riddle | Solution | Lexicographic Sorting |
| 12. | February 2008 | Riddle | Solution | Board Game Strategies |
| 11. | January 2008 | Riddle | Solution | QCPL |
| 10. | December 2007 | Riddle | Solution | One-to-one Functions |
| 9. | November 2007 | Riddle | Solution | License Plate Numbers |
| 8. | October 2007 | Riddle | Solution | Jigsaw Puzzles |
| 7. | September 2007 | Riddle | Solution | Clique Partitioning |
| 6. | August 2007 | Riddle | Solution | Three Points through every Line |
| 5. | July 2007 | Riddle | Solution | Digit Anagrams |
| 4. | June 2007 | Riddle | Solution | Mesh Animals |
| 3. | May 2007 | Riddle | Solution | Chico and Dico |
| 2. | April 2007 | Riddle | Solution | 3025 |
| 1. | March 2007 | Riddle | Solution | Primitive Polynomials |
Enjoy!