Table:
0
A
B
C
D
E
1
Seat
Series 1
Series 3
Series 4
Series 5
2
1
Niall O'Farrell
Niall O'Farrell
Niall O'Farrell
Peter Casey (businessman)
3
2
Bobby Kerr
Bobby Kerr
Bobby Kerr
Ramona Nicholas
4
3
Sarah Newman
Norah Casey
Sean O'Sullivan
Sean O'Sullivan
5
4
Gavin Duffy
Gavin Duffy
Gavin Duffy
Gavin Duffy
6
5
Seán Gallagher
Seán Gallagher
Norah Casey
Barry O'Sullivan

Questions and formulas:
Question: What is the series 3 with gavin duffy in series 5?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,E1="gavin duffy"),3))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E6,E2:E6="gavin duffy"),3))
Level: medium
Question: What is the series 4 with sarah newman in series 1?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,B1="sarah newman"),4))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E6,B2:B6="sarah newman"),4))
Level: medium
Question: What is the series 3 with more than 4 seats?
Formula: LET(query1,SUMMARIZE(C1,SUMX(A1)),FILTER(query1,CHOOSECOLS(query1,2)>4))
Formula2: LET(query1,SUMMARIZE(C2:C6,SUMX(A2:A6)),FILTER(query1,CHOOSECOLS(query1,2)>4))
Level: hard
Question: What is the total number of seats with gavin duffy in series 4?
Formula: SUMIFS(A1,D1,"gavin duffy")
Formula2: SUMIFS(A2:A6,D2:D6,"gavin duffy")
Level: easy