Given the following table:
| ENO | SALARY |
|---|---|
| A101 | 4000 |
| B109 | NULL |
| C508 | 6000 |
| A305 | 2000 |
State the output of the following query:
SELECT COUNT(SALARY) FROM EMPLOYEE;
| List-I (Aggregate function) | List-II (Description) |
|---|---|
(A) count(marks) | (III) Count all non null values of marks column |
(B) count() | (I) Count all rows |
(C) avg(marks) | (II) Finding average of non null values of marks |
(D) sum(marks) | (IV) Finding sum of all marks |
| List-I | List-II |
|---|---|
| (A) Primary key | (III) Attribute used to uniquely identify a tuple. |
| (B) Degree | (I) Total number of attributes in a table. |
| (C) Foreign key | (II) Attribute used to relate two tables. |
| (D) Constraint | (IV) A restriction on the type of data that can be inserted in a column. |
The marks out of 50 obtained by 100 students in a test are given below:
| Marks obtained | 20 | 25 | 28 | 29 | 33 | 38 | 42 | 43 |
|---|---|---|---|---|---|---|---|---|
| Number of students | 6 | 20 | 24 | 28 | 15 | 4 | 2 | 1 |
Find: \(3\text{ mode} - 2\text{ median}\)