Table:
0
A
B
C
D
E
1
Name
Design
Manufacturer
Acquired
Disposed
2
Adler
1A1
Stephenson 1835
1835
sold 1857
3
Pfeil
1A1
Stephenson 1836
1836
sold
4
Nürnberg-Fürth
1A1
Henschel 1852/14
1852
scrapped 1889
5
Phoenix
1A1
Maffei 1853/127
1853
scrapped 1869
6
Adler II
1A1
Maffei 1857/279
1857
scrapped 1889
7
Johannes Scharrer
1A1
Henschel 1865/108
1865
scrapped 1887
8
Faust
1A1
Maffei 1845/6
1872
scrapped 1881
9
Henlein
1A1
Maffei 1845/8
1873
scrapped 1880
10
Wallenstein
1A1
Kessler 1845/30
1875
scrapped 1885
11
Bavaria
Bn2t
Maffei 1879/1204
1879
sold 1923
12
Pegnitz
Bn2t
Maffei 1880/1224
1880
sold 1923
13
Franconia
Bn2t
Maffei 1881/1248
1881
sold 1923
14
Daniel Ley
1Bn2t
Maffei 1886/1414
1886
sold 1923
15
Johannes Scharrer II
Bn2t
Maffei 1887/1453
1887
sold 1923
16
Nürnberg-Fürth II
Bn2t
Maffei 1889/1538
1889
sold 1923
17
Germania
1Bn2t
Maffei 1906/2511
1906
sold 1923
18
Ludwig
1Bn2t
Maffei 1906/2549
1906
sold 1923

Questions and formulas:
Question: What is the average year for Wallenstein with 1a1 design?
Formula: AVERAGE(FILTER(D1, (B1="1a1")*(A1="wallenstein")))
Formula2: AVERAGE(FILTER(D2:D18, (B2:B18="1a1")*(A2:A18="wallenstein")))
Level: easy
Question: What design was acquired in 1875?
Formula: LET(query1,SUMMARIZE(B1,SUMX(D1)),FILTER(query1,CHOOSECOLS(query1,2)=1875))
Formula2: LET(query1,SUMMARIZE(B2:B18,SUMX(D2:D18)),FILTER(query1,CHOOSECOLS(query1,2)=1875))
Level: hard