Question

Match List-I with List-II

List-I AGGREGATE FUNCTIONS	List-II DESCRIPTION
(A) COUNT()	(I) Returns the average of the values in a specified column
(B) AVG()	(II) Returns the number of records in a table
(C) COUNT(*)	(III) Truncate numerical values to a specified position
(D) ROUND()	(IV) Returns the number of values in a specified column, ignoring NULL values

Choose the correct answer from the options given below:

• (A) - (IV), (B) - (III), (C) - (II), (D) - (I)
• (A) - (II), (B) - (I), (C) - (IV), (D) - (III)
• (A) - (IV), (B) - (I), (C) - (II), (D) - (III)
• (A) - (IV), (B) - (I), (C) - (III), (D) - (II)

Hint:

COUNT(*) counts rows, COUNT(column) skips NULLs, AVG gives mean, ROUND fixes decimal places.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Aggregate functions work on a group of values and return a single value. COUNT, AVG, SUM, MIN and MAX are common ones. ROUND is a math function that works on a single value.

Step 2: Match (A) COUNT().
COUNT(column) counts the values in that column and skips NULL values. This matches (IV).

Step 3: Match (B) AVG().
AVG(column) returns the average of the values in a column. This matches (I).

Step 4: Match (C) COUNT(*).
COUNT(*) counts all rows (records) of the table, even when some columns are NULL. This matches (II).

Step 5: Match (D) ROUND().
ROUND(number, d) rounds or truncates a numeric value to a stated number of decimal positions. This matches (III).

Step 6: Check option 1.
It pairs (B) with (III) and (D) with (I). AVG does not round and ROUND does not average. So option 1 is wrong.

Step 7: Check option 2.
It pairs (A) with (II), but COUNT(column) ignores NULLs and so is not the record count. So option 2 is wrong.

Step 8: Check option 3.
It gives (A)-(IV), (B)-(I), (C)-(II), (D)-(III). All four pairs agree with the matches above. So option 3 is correct.

Step 9: Check option 4.
It pairs (C) with (III) and (D) with (II). COUNT(*) does not truncate values. So option 4 is wrong.

Final Answer:
The correct match is A-IV, B-I, C-II, D-III, option 3. \[ \boxed{(A) - (IV), (B) - (I), (C) - (II), (D) - (III)} \]