New York Not-For-Profit Corporation Law Section 707 - Quorum of directors.

707. Quorum of directors.
Unless  a  greater  proportion  is  required by this chapter or by the
  certificate of incorporation or by a by-law adopted by  the  members,  a
  majority  of  the  entire  board  shall  constitute  a  quorum  for  the
  transaction of business or of any specified  item  of  business,  except
  that  the certificate of incorporation or the by-laws may fix the quorum
  at less than a majority of the entire board, provided that in  the  case
  of  a  board  of  fifteen  members  or less the quorum shall be at least
  one-third of the entire number of members and in the case of a board  of
  more than fifteen members the quorum shall be at least five members plus
  one  additional  member  for  every ten members (or fraction thereof) in
  excess of fifteen.

Last modified: February 3, 2019