Table:
0
A
B
C
D
E
F
G
H
1
perpetrator id
people id
date
year
location
country
killed
injured
2
1
1
04.26 April 26/27
1982
Uiryeong
South Korea
56
37
3
2
3
11.18 Nov. 18
1995
Zhaodong
China
32
16
4
3
4
05.21 May 21
1938
Kaio
Japan
30
3
5
4
6
09.20 Sep. 20
1994
Beijing
China
23
80
6
5
8
04.00 April
1950
Nainital
India
22
0

Questions and formulas:
Question: How many perpetrators are there?
Formula: SUM(A1)
Formula2: SUM(A2:A6)
Level: easy
Question: List the number of people injured by perpetrators in ascending order.
Formula: SORTBY(H1,H1,1)
Formula2: SORTBY(H2:H6,H2:H6,1)
Level: easy
Question: What is the location of the perpetrator with the largest kills.
Formula: LET(a,SORTBY(E1,G1,-1),FILTER(a,SEQUENCE(ROWS(a))<=1))
Formula2: LET(a,SORTBY(E2:E6,G2:G6,-1),FILTER(a,SEQUENCE(ROWS(a))<=1))
Level: hard
Question: Show each country and the corresponding number of perpetrators there.
Formula: SUMMARIZE(F1,SUMX(A1))
Formula2: SUMMARIZE(F2:F6,SUMX(A2:A6))
Level: easy
Question: What is the country that has the most perpetrators?
Formula: TAKE(SORT(SUMMARIZE(F1,SUMX(A1)), 2, -1), 1)
Formula2: TAKE(SORT(SUMMARIZE(F2:F6,SUMX(A2:A6)), 2, -1), 1)
Level: hard
Question: What are the countries that have at least two perpetrators?
Formula: LET(query1,SUMMARIZE(F1,SUMX(A1)),FILTER(query1,CHOOSECOLS(query1,3)>=2))
Formula2: LET(query1,SUMMARIZE(F2:F6,SUMX(A2:A6)),FILTER(query1,CHOOSECOLS(query1,3)>=2))
Level: hard
Question: How many distinct locations of perpetrators are there?
Formula: ROWS(UNIQUE(E1))
Formula2: ROWS(UNIQUE(E2:E6))
Level: easy
Question: Number of murderers in each country
Formula: SUMMARIZE(F1,SUMX(A1))
Formula2: SUMMARIZE(F2:F6,SUMX(A2:A6))
Level: easy
Question: The country with the most perpetrators.
Formula: TAKE(SORT(SUMMARIZE(F1,SUMX(A1)), 2, -1), 1)
Formula2: TAKE(SORT(SUMMARIZE(F2:F6,SUMX(A2:A6)), 2, -1), 1)
Level: hard
Question: Show all countries with two or more perpetrators.
Formula: LET(query1,SUMMARIZE(F1,SUMX(A1)),FILTER(query1,CHOOSECOLS(query1,3)>=2))
Formula2: LET(query1,SUMMARIZE(F2:F6,SUMX(A2:A6)),FILTER(query1,CHOOSECOLS(query1,3)>=2))
Level: hard
Question: Total number of locations and perpetrators respectively 
Formula: HSTACK(ROWS(UNIQUE(E1)), SUM(A1))
Formula2: HSTACK(ROWS(UNIQUE(E2:E6)), SUM(A2:A6))
Level: hard
Question: All years
Formula: UNIQUE(D1)
Formula2: UNIQUE(D2:D6)
Level: easy
Question: Total number of perpetrators.
Formula: SUM(A1)
Formula2: SUM(A2:A6)
Level: easy
Question: Where is the most prolific murderer from?
Formula: TAKE(SORT(SUMMARIZE(HSTACK(E1,A1),SUMX(G1)), 3, -1), 1)
Formula2: TAKE(SORT(SUMMARIZE(HSTACK(E2:E6,A2:A6),SUMX(G2:G6)), 3, -1), 1)
Level: hard
Question: The number of perpetrators.
Formula: SUM(A1)
Formula2: SUM(A2:A6)
Level: easy
Question: Where is perpetrator with the most kills from?
Formula: LET(a,HSTACK(E1,A1),b,A1,c,CHOOSECOLS(TAKE(SORT(SUMMARIZE(A1,SUMX(G1)), 2, -1), 1),1),UNIQUE(FILTER(a,NOT(ISNA(XLOOKUP(b,c,c))))))
Formula2: LET(a,HSTACK(E2:E6,A2:A6),b,A2:A6,c,CHOOSECOLS(TAKE(SORT(SUMMARIZE(A2:A6,SUMX(G2:G6)), 2, -1), 1),1),UNIQUE(FILTER(a,NOT(ISNA(XLOOKUP(b,c,c))))))
Level: hard
Question: How many perpetrators in each country?
Formula: SUMMARIZE(F1,SUMX(A1))
Formula2: SUMMARIZE(F2:F6,SUMX(A2:A6))
Level: easy
Question: The countries with at least two perpetrators.
Formula: LET(query1,SUMMARIZE(F1,SUMX(A1)),FILTER(query1,CHOOSECOLS(query1,3)>=2))
Formula2: LET(query1,SUMMARIZE(F2:F6,SUMX(A2:A6)),FILTER(query1,CHOOSECOLS(query1,3)>=2))
Level: hard
Question: The number of locations and perpetrators.
Formula: HSTACK(ROWS(UNIQUE(E1)), SUM(A1))
Formula2: HSTACK(ROWS(UNIQUE(E2:E6)), SUM(A2:A6))
Level: hard
Question: The years
Formula: UNIQUE(D1)
Formula2: UNIQUE(D2:D6)
Level: easy