15. Setti‘srule: C9=6 Setti‘s rule: the number of columns and rows, where a digit appears, must be exactly the same. 6 must appear in every column 6 must appear in row C
26. Weekly Extreme Str8ts Puzzle #31www.str8ts.com Solution by SlowThinker Note: There are other (maybe easier or more logical) ways to solve this puzzle.