Table:
0
A
B
C
D
E
F
1
District
Incumbent
Party
First elected
Result
Candidates
2
Louisiana 1
James O'Connor
Democratic
1918
Re-elected
James O'Connor (D) Unopposed
3
Louisiana 2
Henry Garland Dupré
Democratic
1908
Re-elected
Henry Garland Dupré (D) Unopposed
4
Louisiana 3
Whitmell P. Martin
Democratic
1914
Re-elected
Whitmell P. Martin (D) Unopposed
5
Louisiana 4
John T. Watkins
Democratic
1904
Lost renomination Democratic hold
John N. Sandlin (D) Unopposed
6
Louisiana 5
Riley Joseph Wilson
Democratic
1914
Re-elected
Riley Joseph Wilson (D) Unopposed
7
Louisiana 6
Jared Y. Sanders, Sr.
Democratic
1916
Retired to run for U.S. Senate Democratic hold
George K. Favrot (D) Unopposed
8
Louisiana 7
Ladislas Lazaro
Democratic
1912
Re-elected
Ladislas Lazaro (D) Unopposed

Questions and formulas:
Question: Who were the candidates when Henry Garland Dupré was incumbent?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:F1,B1="Henry Garland Dupré"),6))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:F8,B2:B8="Henry Garland Dupré"),6))
Level: medium
Question: How many candidates were there when Henry Garland Dupré was the incumbent? 
Formula: ROWS(UNIQUE(FILTER(F1, B1="Henry Garland Dupré")))
Formula2: ROWS(UNIQUE(FILTER(F2:F8, B2:B8="Henry Garland Dupré")))
Level: medium
Question: What district did James O'Connor belong to?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:F1,B1="James O'Connor"),1))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:F8,B2:B8="James O'Connor"),1))
Level: medium