What is the name of the social event that was attended by the vice president of the Student_Club located at 900 E. Washington St.?
name of social event refers to event_name where type = 'Social'; 'Vice President' is position; located at refers to location
SELECT T2.event_name FROM attendance AS T1 INNER JOIN event AS T2 ON T2.event_id = T1.link_to_event INNER JOIN member AS T3 ON T1.link_to_member = T3.member_id WHERE T3.position = 'Vice President' AND T2.location = '900 E. Washington St.' AND T2.type = 'Social'