Table:
0
A
B
C
D
E
F
G
H
I
J
1
code
room id
check in
check out
rate
last name
first name
adults
kids
reservations
2
1
101
 Oct 23, 2010
 Oct 25, 2010
SWEAZY
ROY
3
4
3
2
102
 Oct 23, 2010
 Oct 25, 2010
SELBIG
CONRAD
3
4
4
3
103
 Oct 23, 2011
23-Sep-10
SELBIG
CONRAD
3
4
5
4
104
 Oct 23, 2012
23-Sep-10
SELBIG
CONRAD
3
4
6
5
105
September 21, 2010
22-Sep-10
DAMIEN
TRACHSEL
3
4

Questions and formulas:
Question: How many kids stay in the rooms reserved by ROY SWEAZY?
Formula: LET(query1,FILTER(A1:J1,(G1="roy")*(F1="sweazy")),SUMMARIZE(CHOOSECOLS(query1,2),SUMX(CHOOSECOLS(query1,9))))
Formula2: LET(query1,FILTER(A2:J6,(G2:G6="roy")*(F2:F6="sweazy")),SUMMARIZE(CHOOSECOLS(query1,2),SUMX(CHOOSECOLS(query1,9))))
Level: hard
Question: How many times does ROY SWEAZY has reserved a room.
Formula: LET(query1,FILTER(A1:J1,(G1="roy")*(F1="sweazy")),SUMMARIZE(CHOOSECOLS(query1,2),COUNTX(CHOOSECOLS(query1,2))))
Formula2: LET(query1,FILTER(A2:J6,(G2:G6="roy")*(F2:F6="sweazy")),SUMMARIZE(CHOOSECOLS(query1,2),COUNTX(CHOOSECOLS(query1,2))))
Level: hard
Question: Find the number of times ROY SWEAZY has reserved a room.
Formula: SUM(FILTER(B1, (G1="roy")*(F1="sweazy")))
Formula2: SUM(FILTER(B2:B6, (G2:G6="roy")*(F2:F6="sweazy")))
Level: easy
Question: How many adults named CONRAD SELBIG checked in on Oct 23, 2010?
Formula: SUM(FILTER(H1, (C1="oct 23, 2010")*(G1="conrad")*(F1="selbig")))
Formula2: SUM(FILTER(H2:H6, (C2:C6="oct 23, 2010")*(G2:G6="conrad")*(F2:F6="selbig")))
Level: easy
Question: Find the number of adults for the room reserved and checked in by CONRAD SELBIG on Oct 23, 2010.
Formula: LET(query1,FILTER(A1:J1,(C1="oct 23, 2010")*(G1="conrad")*(F1="selbig")),SUMMARIZE(CHOOSECOLS(query1,2),SUMX(CHOOSECOLS(query1,8))))
Formula2: LET(query1,FILTER(A2:J6,(C2:C6="oct 23, 2010")*(G2:G6="conrad")*(F2:F6="selbig")),SUMMARIZE(CHOOSECOLS(query1,2),SUMX(CHOOSECOLS(query1,8))))
Level: hard
Question: How many rooms did roy sweazy reserve? 
Formula: SUM(FILTER(B1, (G1="roy")*(F1="sweazy")))
Formula2: SUM(FILTER(B2:B6, (G2:G6="roy")*(F2:F6="sweazy")))
Level: easy
Question: Number of rooms reserved by roy sweazy.
Formula: SUM(FILTER(B1, (G1="roy")*(F1="sweazy")))
Formula2: SUM(FILTER(B2:B6, (G2:G6="roy")*(F2:F6="sweazy")))
Level: easy
Question: The number of rooms of roy sweazy.
Formula: SUM(FILTER(B1, (G1="roy")*(F1="sweazy")))
Formula2: SUM(FILTER(B2:B6, (G2:G6="roy")*(F2:F6="sweazy")))
Level: easy