lower bound = 6

C(10,5,2) = 6

Method of Construction: simple construction: induced on c(11,6,3) covering

Lower Bound: Schonheim

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