lower bound = 5

C(12,7,2) = 5

Method of Construction: lex covering

Lower Bound: Bounds for fixed number of blocks

  1  2  3  4  5  6  7
  1  2  8  9 10 11 12
  3  4  5  6  8  9 10
  3  4  5  6  7 11 12
  1  2  3  7  8  9 10