Table:
0
A
B
C
D
E
1
County
Town/City
Milepost
Station
Connections
2
Fairfield
Stratford
59.0
Stratford (Limited service)
Shore Line East GBTA : 1, 10, 16, 23, Coastal Link
3
New Haven
Milford
Waterbury Branch splits
Waterbury Branch splits
Waterbury Branch splits
4
New Haven
Derby
69.5
Derby–Shelton
GBTA :15, 23 CTTransit New Haven : F
5
New Haven
Ansonia
71.1
Ansonia
CTTransit New Haven : F
6
New Haven
Seymour
75
Seymour
CTTransit New Haven : F
7
New Haven
Beacon Falls
78.5
Beacon Falls
N/A
8
New Haven
Naugatuck
82.5
Naugatuck
CTTransit Waterbury : N1

Questions and formulas:
Question: How many counties are at milepost 69.5? 
Formula: ROWS(UNIQUE(FILTER(A1, C1=69.5)))
Formula2: ROWS(UNIQUE(FILTER(A2:A8, C2:C8=69.5)))
Level: medium
Question: In what city or town is Stratford (limited service)? 
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,D1="Stratford (Limited service)"),2))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E8,D2:D8="Stratford (Limited service)"),2))
Level: medium
Question: At what city or town is milepost 71.1? 
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,C1=71.1),2))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E8,C2:C8=71.1),2))
Level: medium
Question: How many towns or cities are at milepost 71.1? 
Formula: ROWS(UNIQUE(FILTER(B1, C1=71.1)))
Formula2: ROWS(UNIQUE(FILTER(B2:B8, C2:C8=71.1)))
Level: medium
Question: At what milepost is Beacon Falls? 
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,B1="Beacon Falls"),3))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E8,B2:B8="Beacon Falls"),3))
Level: medium