lower bound = 20

C(11,5,3) = 20

Method of Construction: simple construction: induced on c(12,6,4) covering

Lower Bound: Schonheim

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