 Dulwich College is a member of an association of how many independent schools?
Dulwich College: Dulwich College is a boarding and day independent school for boys in Dulwich in southeast London, England. Dulwich College:  It is a member of both the Headmasters' and Headmistresses' Conference and the Eton Group. Headmasters' and Headmistresses' Conference: The Headmasters' and Headmistresses' Conference (HMC) is an association of the headmasters or headmistresses of 283 independent schools (both boarding schools and day schools) in the United Kingdom, Crown dependencies and the Republic of Ireland.
283