Table:
0
A
B
C
D
E
1
course id
author id
subject id
course name
course description
2
1
8
1
database
database
3
2
6
1
advanced database
advanced database
4
3
15
1
operating system
operating system
5
4
14
2
Art history
Art history
6
5
11
1
data structure
data structure
7
6
12
3
English
English
8
7
8
3
French
French
9
8
4
3
Japanese
Japanese
10
9
13
1
AI
AI
11
10
5
3
Writing in French
Writing in French
12
11
9
3
Spanish
Spanish
13
12
5
2
European Arts
European Arts
14
13
13
1
machine learning
machine learning
15
14
6
2
modern Arts
modern Arts
16
15
14
2
Chinese Painting
Chinese Painting

Questions and formulas:
Question: How many courses are there in total?
Formula: SUM(A1)
Formula2: SUM(A2:A16)
Level: easy
Question: Find the total number of courses offered.
Formula: SUM(A1)
Formula2: SUM(A2:A16)
Level: easy
Question: What are the descriptions of the courses with name "database"?
Formula: FILTER(E1,D1="database")
Formula2: FILTER(E2:E16,D2:D16="database")
Level: easy
Question: Return the description for the courses named "database".
Formula: FILTER(E1,D1="database")
Formula2: FILTER(E2:E16,D2:D16="database")
Level: easy
Question: How many courses are offered?
Formula: SUM(A1)
Formula2: SUM(A2:A16)
Level: easy
Question: Database course's description and id 
Formula: LET(query1,FILTER(A1:E1,D1="database"),UNIQUE(CHOOSECOLS(query1,5,1)))
Formula2: LET(query1,FILTER(A2:E16,D2:D16="database"),UNIQUE(CHOOSECOLS(query1,5,1)))
Level: hard
Question: The description of the course called database.
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:E1,D1="database"),5))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:E16,D2:D16="database"),5))
Level: medium
Question: The number of the courses.
Formula: SUM(A1)
Formula2: SUM(A2:A16)
Level: easy
Question: The description and id of the course called database.
Formula: LET(query1,FILTER(A1:E1,D1="database"),UNIQUE(CHOOSECOLS(query1,5,1)))
Formula2: LET(query1,FILTER(A2:E16,D2:D16="database"),UNIQUE(CHOOSECOLS(query1,5,1)))
Level: hard