Table:
0
A
B
C
D
E
1
Title
Length
Writer
Director
Airdate
2
"Episode 1"
60 minutes
Sarah Phelps
Coky Giedroyc
18 December 2007
3
"Episode 2"
30 minutes
Sarah Phelps
Coky Giedroyc
19 December 2007
4
"Episode 3"
30 minutes
Sarah Phelps
Coky Giedroyc
20 December 2007
5
"Episode 4"
30 minutes
Sarah Phelps
Coky Giedroyc
21 December 2007
6
"Episode 5"
30 minutes
Sarah Phelps
Coky Giedroyc
22 December 2007

Questions and formulas:
Question: The length of 30 minutes aired on what date?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,B1="30 minutes"),5))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E6,B2:B6="30 minutes"),5))
Level: medium
Question: When did the length of 60 minutes air?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,B1="60 minutes"),5))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E6,B2:B6="60 minutes"),5))
Level: medium