Table:
0
A
B
C
D
E
F
1
id
brand
name
focal length mm
max aperture
camera lens
2
1
Olympus
Olympus 15mm f/8.0 Body Cap
15.0
8.0
3
2
Olympus
Olympus M.Zuiko Digital ED 45mm f/1.8
45.0
1.8
4
3
Olympus
Olympus M.Zuiko Digital ED 75mm f/1.8
75.0
1.8
5
4
Panasonic
Panasonic Leica DG Summilux 25mm f /1.4 Asph.
25.0
1.4
6
5
Panasonic
Panasonic Leica DG Nocticron 42.5mm f /1.2
42.5
1.2
7
6
Panasonic
Panasonic Lumix G 150mm f /2.8
150.0
2.8
8
7
Schneider Kreuznach
Schneider Kreuznach Super Angulon 14mm f /2.0
14.0
2.0
9
8
Schneider Kreuznach
Schneider Kreuznach Xenon 30mm f /1.4
30.0
1.4
10
9
Sigma
Sigma 19mm f2.8 DN
19.0
2.8
11
10
Sigma
Sigma 19mm f2.8 EX DN
19.0
2.8
12
11
Sigma
Sigma 30mm f2.8 DN
30.0
2.8

Questions and formulas:
Question: How many camera lenses have a focal length longer than 15 mm?
Formula: ROWS(UNIQUE(LET(a,F1,b,F1,c,INDEX(LET(query1,SUMMARIZE(F1,SUMX(D1)),FILTER(query1,CHOOSECOLS(query1,2)>15)),,1),FILTER(a,NOT(ISNA(XLOOKUP(b,c,c)))))))
Formula2: ROWS(UNIQUE(LET(a,F2:F12,b,F2:F12,c,INDEX(LET(query1,SUMMARIZE(F2:F12,SUMX(D2:D12)),FILTER(query1,CHOOSECOLS(query1,2)>15)),,1),FILTER(a,NOT(ISNA(XLOOKUP(b,c,c)))))))
Level: hard
Question: Find the brand and name for each camera lens, and sort in descending order of max aperture.
Formula: SORT(SUMMARIZE(HSTACK(B1,C1,F1),SUMX(E1)), 4, -1)
Formula2: SORT(SUMMARIZE(HSTACK(B2:B12,C2:C12,F2:F12),SUMX(E2:E12)), 4, -1)
Level: hard
Question: How many different kinds of brands are there
Formula: ROWS(UNIQUE(B1))
Formula2: ROWS(UNIQUE(B2:B12))
Level: easy
Question: Number of camera lens which have a focal length exceeding 15mm.
Formula: ROWS(UNIQUE(LET(a,F1,b,F1,c,INDEX(LET(query1,SUMMARIZE(F1,SUMX(D1)),FILTER(query1,CHOOSECOLS(query1,2)>15)),,1),FILTER(a,NOT(ISNA(XLOOKUP(b,c,c)))))))
Formula2: ROWS(UNIQUE(LET(a,F2:F12,b,F2:F12,c,INDEX(LET(query1,SUMMARIZE(F2:F12,SUMX(D2:D12)),FILTER(query1,CHOOSECOLS(query1,2)>15)),,1),FILTER(a,NOT(ISNA(XLOOKUP(b,c,c)))))))
Level: hard
Question: the respective number of camera lens and brands
Formula: HSTACK(ROWS(UNIQUE(F1)), ROWS(UNIQUE(B1)))
Formula2: HSTACK(ROWS(UNIQUE(F2:F12)), ROWS(UNIQUE(B2:B12)))
Level: hard
Question: the number of camera lens with focal length longer than 15mm
Formula: ROWS(UNIQUE(FILTER(F1, D1>15)))
Formula2: ROWS(UNIQUE(FILTER(F2:F12, D2:D12>15)))
Level: medium