Table:
0
A
B
C
D
E
1
Manufacturer
Type
Quantity
LMMR Name
GWR No.
2
Andrew Barclay Sons & Co.
0-6-0T
1
George Waddell
312
3
Hudswell Clarke
0-6-0T
2
Tarndune
339
4
Hudswell Clarke
0-6-0ST
1
Hilda
359
5
Manning Wardle
0-6-0T
1
Victory
704
6
Hudswell Clarke
0-6-0T
1
Ravelston
803
7
Hudswell Clarke
0-6-0T
1
Merkland
937
8
Avonside Engine Company
0-6-0T
1
Great Mountain
944
9
Fox, Walker & Co.
0-6-0ST
1
Seymour Clarke
969

Questions and formulas:
Question: Which Manufacturer has a Quantity of 1, and has the LMMR name Great Mountain?
Formula: LET(query1,LET(query1,FILTER(A1:E1,D1="great mountain"),SUMMARIZE(CHOOSECOLS(query1,1),SUMX(CHOOSECOLS(query1,3)))),FILTER(query1,CHOOSECOLS(query1,2)=1))
Formula2: LET(query1,LET(query1,FILTER(A2:E9,D2:D9="great mountain"),SUMMARIZE(CHOOSECOLS(query1,1),SUMX(CHOOSECOLS(query1,3)))),FILTER(query1,CHOOSECOLS(query1,2)=1))
Level: hard