Table:
0
A
B
C
D
E
1
Road race
Distance
Location
Country
Month held
2
Maraton de Santiago
Marathon
Santiago
Chile
April
3
Pyongyang Marathon
Marathon
Pyongyang
North Korea
April
4
Brighton Marathon
Marathon
Brighton
United Kingdom
April
5
Nagano Marathon
Marathon
Nagano
Japan
April
6
Düsseldorf Marathon
Marathon
Düsseldorf
Germany
April
7
Hannover Marathon
Marathon
Hannover
Germany
May
8
Riga Marathon
Marathon
Riga
Latvia
May
9
Gifu Seiryu Half Marathon
Half marathon
Gifu
Japan
May
10
Edinburgh Marathon
Marathon
Edinburgh
United Kingdom
May
11
Corrida de Langueux
10 km
Langueux
France
June
12
Vidovdan 10K
10 km
Brčko
Bosnia and Herzegovina
June
13
Gold Coast Marathon
Marathon
Gold Coast
Australia
July
14
Siberian International Marathon
Marathon
Omsk
Russia
September
15
Paris 20K
20 km
Paris
France
October
16
Beirut Marathon
20 km
Beirut
Lebanon
November
17
Alpes-Maritimes Marathon
Marathon
Nice
France
November
18
Valencia Marathon
Marathon
Valencia
Spain
November

Questions and formulas:
Question: What race is held in Germany in the month of May? 
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,(D1="Germany")*(E1="May")),1))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E18,(D2:D18="Germany")*(E2:E18="May")),1))
Level: medium
Question: How many times a year is the Brighton Marathon held?
Formula: ROWS(UNIQUE(FILTER(E1, (B1="Marathon")*(C1="Brighton"))))
Formula2: ROWS(UNIQUE(FILTER(E2:E18, (B2:B18="Marathon")*(C2:C18="Brighton"))))
Level: medium
Question: What month is the Paris 20k Road Race held?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,C1="Paris"),5))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E18,C2:C18="Paris"),5))
Level: medium
Question: How many times a year is the Paris 20k road race held?
Formula: ROWS(UNIQUE(FILTER(E1, A1="Paris 20K")))
Formula2: ROWS(UNIQUE(FILTER(E2:E18, A2:A18="Paris 20K")))
Level: medium
Question: What is the name of the road race held in Omsk, Russia?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,C1="Omsk"),1))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E18,C2:C18="Omsk"),1))
Level: medium