Table:
0
A
B
C
D
E
F
G
H
1
Race name
Dist (miles)
Course
Prize
Odds
Runners
Place
Runner-up
2
Match race v. Speedwell
4
Newmarket
500 guineas
not known
2
1
Speedwell
3
Match race v. Speedwell
not known
Newmarket
500 guineas
not known
2
1
forfeit
4
Trial v. Almanzor and Brown Betty
4
Newmarket
none
not known
3
1
not known
5
Match race v. Chaunter
6
Newmarket
1000 guineas
not known
2
1
Chaunter
6
Race v. Stripling and Bridgewater's Lonsdale Mare
not known
Newmarket
100 guineas
not known
3
1
forfeit
7
Match race v. Bobsey
not known
Newmarket
100 guineas
not known
2
1
forfeit

Questions and formulas:
Question: Which race had a distance of 4 miles where the runner-up was not known?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:H1,(B1=4)*(H1="not known")),1))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:H7,(B2:B7=4)*(H2:H7="not known")),1))
Level: medium