Table:
0
A
B
C
D
E
1
Client
Years of Operation
Area of Operation
Country
Services
2
Agoco
1991-current
Sarir field
Libya
Drilling, workover
3
Lasmo
1993-94
Wadi Borjuj
Libya
Drilling, workover
4
Waha
1994
El Zahra
Libya
Drilling, workover
5
IPC-Dublin
1997-97
Kilwa
Tanzania
Drilling
6
OMV
1997
Field 103
Libya
Drilling, workover
7
Fina
1997
El Hamada
Libya
Drilling, workover
8
Marathon
1998
Manzala field
Egypt
Drilling
9
Khalda/ Repsol
1998-99
West Desert
Egypt
Drilling
10
Total
1999-current
El Mabrouk
Libya
Drilling
11
Agiba-Agip
1999
West Desert
Egypt
Drilling
12
IPLL
1999-current
El Naka field
Libya
Drilling
13
SOC
2000-current
SOC fields
Libya
Drilling
14
Veba
2000
Different fields
Libya
Drilling, workover
15
Perenco Oil Co.
2000-01
EchiraX Concession
Gabon
Drilling
16
Zueitina
2001-current
Field 103
Libya
Drilling, workover

Questions and formulas:
Question: Where is the area of operation that had drilling during the year 1999?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,(E1="drilling")*(B1=1999)),3))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E16,(E2:E16="drilling")*(B2:B16=1999)),3))
Level: medium
Question: What country did the client Agiba-agip work in?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,A1="agiba-agip"),4))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E16,A2:A16="agiba-agip"),4))
Level: medium
Question: What years was soc a client?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,A1="soc"),2))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E16,A2:A16="soc"),2))
Level: medium
Question: What years was El Mabrouk the area of operation?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,C1="el mabrouk"),2))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E16,C2:C16="el mabrouk"),2))
Level: medium
Question: What services were in the area of operation Wadi Borjuj?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,C1="wadi borjuj"),5))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E16,C2:C16="wadi borjuj"),5))
Level: medium