user: Question: Name the total number of founded for Public and 780 enrollment
Columns: ['Institution', 'Nickname', 'Location', 'Founded', 'Type', 'Enrollment', 'Current Conference']
Types: ['text', 'text', 'text', 'real', 'text', 'text', 'text']
Sample row: ['Black Hills State University', 'Yellow Jackets', 'Spearfish, South Dakota', 1881.0, 'Public', '4,739', 'RMAC (NCAA Division II)']
SQL:

assistant: SELECT COUNT("Founded") FROM "Table" WHERE "Type" = 'Public' AND "Enrollment" = '780';