Table:
0
A
B
C
D
E
1
Line
Colour
Route
Length
Stations
2
U 1
red
Reumannplatz – Leopoldau
14.6km (9.1mi)
19
3
U 2
purple
Karlsplatz – Seestadt
16.7km (10.4mi)
20
4
U 3
orange
Ottakring – Simmering
13.5km (8.4mi)
21
5
U 4
green
Hütteldorf – Heiligenstadt
16.5km (10.3mi)
20
6
U 6
brown
Siebenhirten – Floridsdorf
17.4km (10.8mi)
24

Questions and formulas:
Question: What is the total number of stations with a line that is u 6?
Formula: SUMIFS(E1,A1,"u 6")
Formula2: SUMIFS(E2:E6,A2:A6,"u 6")
Level: easy
Question: Which route has 21 stations?
Formula: LET(query1,SUMMARIZE(C1,SUMX(E1)),FILTER(query1,CHOOSECOLS(query1,2)=21))
Formula2: LET(query1,SUMMARIZE(C2:C6,SUMX(E2:E6)),FILTER(query1,CHOOSECOLS(query1,2)=21))
Level: hard
Question: Which line was green?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,B1="green"),1))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E6,B2:B6="green"),1))
Level: medium