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📐 Mathematics  ·  Sets  ·  JEE

The set {x : x is a natural number less than 4} in roster form is:

Answer: {1, 2, 3}.

  • A {1, 2, 3}
  • B {1, 2, 3, 4}
  • C {0, 1, 2, 3}
  • D {2, 3, 4}

Correct answer: A. {1, 2, 3}

Explanation: Natural numbers less than 4 are 1, 2 and 3.

Set Operations: Union, Intersection, ComplementUABA∩BOutside both circles = (A∪B)' = A'∩B' (De Morgan)A∪B = everything in either circle; A∩B = only the overlap

A Venn diagram makes set identities visual: A∪B is everything inside either circle, A∩B is only the overlap, and the region outside both circles represents the complement of their union - directly illustrating De Morgan's law (A∪B)′ = A′∩B′.

Concept context

Types of sets, operations (union/intersection/complement), relations, and types of functions with domain and range

Read the full Sets notes →