user: Question: When was the Tennessee 3 district incumbent first elected? 
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Tennessee 1', 'B. Carroll Reece', 'Republican', 1932.0, 'Retired Republican hold', 'Dayton E. Phillips (R) Unopposed']
SQL:

assistant: SELECT "First elected" FROM "Table" WHERE "District" = 'Tennessee 3';