Table:
0
A
B
C
D
E
1
name
phone id
memory in g
carrier
price
2
IPhone 5s
1
32
Sprint
320
3
IPhone 6
5
128
Sprint
480
4
IPhone 6s
2
128
TMobile
699
5
IPhone 7
4
16
TMobile
899
6
IPhone X
3
64
TMobile
1000

Questions and formulas:
Question: How many phones are there?
Formula: SUM(B1)
Formula2: SUM(B2:B6)
Level: easy
Question: List the names of phones in ascending order of price.
Formula: SORTBY(A1,E1,1)
Formula2: SORTBY(A2:A6,E2:E6,1)
Level: easy
Question: Show the names of phones with carrier either "Sprint" or "TMobile".
Formula: FILTER(A1,(D1="Sprint")+(D1="TMobile"))
Formula2: FILTER(A2:A6,(D2:D6="Sprint")+(D2:D6="TMobile"))
Level: easy
Question: What is the carrier of the most expensive phone?
Formula: LET(a,SORTBY(D1,E1,-1),FILTER(a,SEQUENCE(ROWS(a))<=1))
Formula2: LET(a,SORTBY(D2:D6,E2:E6,-1),FILTER(a,SEQUENCE(ROWS(a))<=1))
Level: hard
Question: Show different carriers of phones together with the number of phones with each carrier.
Formula: SUMMARIZE(D1,SUMX(B1))
Formula2: SUMMARIZE(D2:D6,SUMX(B2:B6))
Level: easy
Question: the number of phones.
Formula: SUM(B1)
Formula2: SUM(B2:B6)
Level: easy
Question: Phone names from cheapest to most expensive.
Formula: SORT(SUMMARIZE(HSTACK(A1,B1),SUMX(E1)), 3, 1)
Formula2: SORT(SUMMARIZE(HSTACK(A2:A6,B2:B6),SUMX(E2:E6)), 3, 1)
Level: hard
Question: What are names and ids of phones carried by sprint or tmobile?
Formula: LET(query1,FILTER(A1:E1,(D1="sprint")+(D1="tmobile")),UNIQUE(CHOOSECOLS(query1,1,2)))
Formula2: LET(query1,FILTER(A2:E6,(D2:D6="sprint")+(D2:D6="tmobile")),UNIQUE(CHOOSECOLS(query1,1,2)))
Level: hard
Question: The carrier of the most expensive phone.
Formula: LET(a,HSTACK(D1,B1),b,B1,c,CHOOSECOLS(TAKE(SORT(SUMMARIZE(B1,SUMX(E1)), 2, -1), 1),1),UNIQUE(FILTER(a,NOT(ISNA(XLOOKUP(b,c,c))))))
Formula2: LET(a,HSTACK(D2:D6,B2:B6),b,B2:B6,c,CHOOSECOLS(TAKE(SORT(SUMMARIZE(B2:B6,SUMX(E2:E6)), 2, -1), 1),1),UNIQUE(FILTER(a,NOT(ISNA(XLOOKUP(b,c,c))))))
Level: hard
Question: How many phones per carrier? 
Formula: SUMMARIZE(D1,SUMX(B1))
Formula2: SUMMARIZE(D2:D6,SUMX(B2:B6))
Level: easy
Question: The names of phones from the cheapest to the most expensive.
Formula: SORT(SUMMARIZE(HSTACK(A1,B1),SUMX(E1)), 3, 1)
Formula2: SORT(SUMMARIZE(HSTACK(A2:A6,B2:B6),SUMX(E2:E6)), 3, 1)
Level: hard
Question: How many phones of each carrier?
Formula: SUMMARIZE(D1,SUMX(B1))
Formula2: SUMMARIZE(D2:D6,SUMX(B2:B6))
Level: easy