Among the projects created by a teacher from New York, how many of them have a donor from the same city?
New York is the donor city; donor from the same city refers to donor from New York in which teacher_ny_teaching_fellow = 't';
SELECT COUNT(T1.projectid) FROM projects AS T1 INNER JOIN donations AS T2 ON T1.projectid = T2.projectid WHERE T1.teacher_ny_teaching_fellow = 't' AND T2.donor_city = 'New York'