UPDATE (1 August): So far, there have been no complete
solutions for the July riddle. The riddle will therefore run one extra month,
but with the following hint:
The riddle asks to find subsets of a set of size
This question came to me while working with Yaniv Erlich on a related problem.
A Steiner system, often denoted
"Using your Head is Permitted" has looked at Steiner systems before. The riddle
for September 2007 had to do with constructing
several Steiner systems of desired sizes with
This month's riddle deals with the construction of Steiner systems with
One mitigation: In 1981, Sloane and Thompson proved that |
## List of solvers:Oded Margalit (3 August 10:20) |

Elegant solutions can be submitted to the puzzlemaster at __riddlesbrand.scso.com__.
Names of solvers will be posted on this page. Notify if you don't want
your name to be mentioned.

The solution will be published at the end of the month.

Enjoy!