Table:
0
A
B
C
D
E
F
G
1
singer id
name
country
song name
song release year
age
is male
2
1
Joe Sharp
Netherlands
You
1992
52
F
3
2
Timbaland
United States
Dangerous
2008
32
T
4
3
Justin Brown
France
Hey Oh
2013
29
T
5
4
Rose White
France
Sun
2003
41
F
6
5
John Nizinik
France
Gentleman
2014
43
T
7
6
Tribal King
France
Love
2016
25
T

Questions and formulas:
Question: How many singers do we have?
Formula: SUM(A1)
Formula2: SUM(A2:A7)
Level: easy
Question: What is the total number of singers?
Formula: SUM(A1)
Formula2: SUM(A2:A7)
Level: easy
Question: What are the names, countries, and ages for every singer in descending order of age?
Formula: SORTBY(CHOOSE({1,2,3},B1,C1,F1),F1,-1)
Formula2: SORTBY(CHOOSE({1,2,3},B2:B7,C2:C7,F2:F7),F2:F7,-1)
Level: easy
Question: What are all distinct countries where singers above age 20 are from?
Formula: UNIQUE(FILTER(C1,F1>20))
Formula2: UNIQUE(FILTER(C2:C7,F2:F7>20))
Level: easy
Question: What are  the different countries with singers above age 20?
Formula: UNIQUE(FILTER(C1,F1>20))
Formula2: UNIQUE(FILTER(C2:C7,F2:F7>20))
Level: easy
Question: Show all countries and the number of singers in each country.
Formula: SUMMARIZE(C1,SUMX(A1))
Formula2: SUMMARIZE(C2:C7,SUMX(A2:A7))
Level: easy
Question: How many singers are from each country?
Formula: SUMMARIZE(C1,SUMX(A1))
Formula2: SUMMARIZE(C2:C7,SUMX(A2:A7))
Level: easy
Question: How many singers have given concerts?
Formula: SUM(A1)
Formula2: SUM(A2:A7)
Level: easy
Question: How many singers have held concerts?
Formula: SUM(A1)
Formula2: SUM(A2:A7)
Level: easy
Question: countries and ids of 20 year old singers
Formula: LET(query1,SUMMARIZE(HSTACK(A1,C1),SUMX(F1)),FILTER(query1,CHOOSECOLS(query1,3)=20))
Formula2: LET(query1,SUMMARIZE(HSTACK(A2:A7,C2:C7),SUMX(F2:F7)),FILTER(query1,CHOOSECOLS(query1,3)=20))
Level: hard
Question: How many singers have given concerts in each country?
Formula: SUMMARIZE(C1,SUMX(A1))
Formula2: SUMMARIZE(C2:C7,SUMX(A2:A7))
Level: easy
Question: number of singers per country
Formula: SUMMARIZE(C1,SUMX(A1))
Formula2: SUMMARIZE(C2:C7,SUMX(A2:A7))
Level: easy
Question: countries and ids of 20 year old singers
Formula: LET(query1,SUMMARIZE(HSTACK(C1,A1),SUMX(F1)),FILTER(query1,CHOOSECOLS(query1,3)=20))
Formula2: LET(query1,SUMMARIZE(HSTACK(C2:C7,A2:A7),SUMX(F2:F7)),FILTER(query1,CHOOSECOLS(query1,3)=20))
Level: hard
Question: Countries and ids for singers aged 20.
Formula: LET(query1,SUMMARIZE(HSTACK(C1,A1),SUMX(F1)),FILTER(query1,CHOOSECOLS(query1,3)=20))
Formula2: LET(query1,SUMMARIZE(HSTACK(C2:C7,A2:A7),SUMX(F2:F7)),FILTER(query1,CHOOSECOLS(query1,3)=20))
Level: hard
Question: Ids and countries for singers who are 20 years old.
Formula: LET(a,HSTACK(C1,A1),b,A1,c,CHOOSECOLS(LET(query1,SUMMARIZE(A1,SUMX(F1)),FILTER(query1,CHOOSECOLS(query1,2)=20)),1),UNIQUE(FILTER(a,NOT(ISNA(XLOOKUP(b,c,c))))))
Formula2: LET(a,HSTACK(C2:C7,A2:A7),b,A2:A7,c,CHOOSECOLS(LET(query1,SUMMARIZE(A2:A7,SUMX(F2:F7)),FILTER(query1,CHOOSECOLS(query1,2)=20)),1),UNIQUE(FILTER(a,NOT(ISNA(XLOOKUP(b,c,c))))))
Level: hard
Question: Number of singers from each country.
Formula: SUMMARIZE(C1,SUMX(A1))
Formula2: SUMMARIZE(C2:C7,SUMX(A2:A7))
Level: easy