Table:
0
A
B
C
D
E
1
AIRLINES
IATA
ICAO
CALLSIGN
COMMENCED OPERATIONS
2
Jetstar Asia Airways
3K
JSA
JETSTAR ASIA
2004
3
Scoot
TZ
SCO
SCOOTER
2012
4
SilkAir
MI
SLK
SILKAIR
1976
5
Singapore Airlines
SQ
SIA
SINGAPORE
1947
6
Singapore Airlines Cargo
SQ
SQC
SINGCARGO
2001
7
Tigerair
TR
TGW
GO CAT
2003
8
Valuair
VF
VLU
VALUAIR
2004

Questions and formulas:
Question: Who is the callsign that has ICAO of SCO?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,C1="sco"),4))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E8,C2:C8="sco"),4))
Level: medium
Question: Who is the commenced operations that has icao of slk?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,C1="slk"),5))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E8,C2:C8="slk"),5))
Level: medium
Question: Who is the call sign that has a commenced operation before 1976?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,E1<1976),4))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E8,E2:E8<1976),4))
Level: medium