Table:
0
A
B
C
D
E
1
Week
Date
Opponent
Result
Attendance
2
1
September 18, 1977
at Oakland Raiders
L 24-0
51,022
3
2
September 25, 1977
at Kansas City Chiefs
W 23-7
56,146
4
3
October 2, 1977
Cincinnati Bengals
W 24-3
40,352
5
4
October 9, 1977
at New Orleans Saints
W 14-0
53,942
6
5
October 16, 1977
New England Patriots
L 24-20
50,327
7
6
October 23, 1977
Kansas City Chiefs
L 21-16
33,010
8
7
October 30, 1977
at Miami Dolphins
W 14-13
40,670
9
8
November 6, 1977
at Detroit Lions
L 20-0
72,559
10
9
November 13, 1977
Denver Broncos
L 17-14
45,211
11
10
November 20, 1977
Oakland Raiders
W 12-7
50,887
12
11
November 27, 1977
at Seattle Seahawks
W 30-28
58,994
13
12
December 4, 1977
Cleveland Browns
W 37-14
37,312
14
13
December 11, 1977
at Denver Broncos
L 17-9
74,905
15
14
December 18, 1977
Pittsburgh Steelers
L 10-9
50,727

Questions and formulas:
Question: When did the Chargers play the Denver Broncos before Week 10?
Formula: LET(query1,LET(query1,FILTER(A1:E1,C1="denver broncos"),SUMMARIZE(CHOOSECOLS(query1,2),SUMX(CHOOSECOLS(query1,1)))),FILTER(query1,CHOOSECOLS(query1,2)<10))
Formula2: LET(query1,LET(query1,FILTER(A2:E15,C2:C15="denver broncos"),SUMMARIZE(CHOOSECOLS(query1,2),SUMX(CHOOSECOLS(query1,1)))),FILTER(query1,CHOOSECOLS(query1,2)<10))
Level: hard