I thought of a riddle myself, inspired off of Nyan Cat's thread, but I'm not so sure I'm right... 11 + 2 = 1 Tell me KHV, is it right? If so, why? HINT: This outside the box... EDIT ; Thanks to Makaze for the clarification.
The clock system is actually Z12, and this equation is true in all subgroups of Z12: Z2, Z3, Z4 and Z6. /nerd