ITPEC FE Subject A April 2026 Question 20

3NF = 2NF with no transitive dependency.

A transitive dependency is a non-key attribute determined by another non-key attribute rather than directly by the key. Removing it is exactly what the third normal form adds on top of 2NF.

The progression is:

• •1NF — no repeating groups; every value is atomic
• •2NF — 1NF plus no partial dependency on part of a composite key
• •3NF — 2NF plus no transitive dependency

Answer (d)

Why not others:
- (b) — "no partial dependency" is the definition of 2NF, already assumed by the question
- (c) — "no repeating group" is the definition of 1NF
- (a) — every relation has at least one candidate key, so a table with none cannot exist

Key rule: Each normal form removes one specific kind of dependency: 1NF repeating groups, 2NF partial dependencies, 3NF transitive dependencies. Options that name the wrong one are describing a lower form.

AI-generated — may contain errors