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📐 Mathematics  ·  Relations and Functions  ·  JEE

The number of onto functions from a set of 3 elements to a set of 2 elements is:

Answer: 6.

  • A 4
  • B 6
  • C 8
  • D 3

Correct answer: B. 6

Explanation: Total functions from 3-element to 2-element set = 2³=8. Subtract non-onto (all map to just one element): 2 such constant functions. By inclusion-exclusion: onto = 8-2=6. Verify: each onto function covers both elements. Answer: 6 onto functions

Concept context

Ordered pairs, Cartesian products, types of relations and functions, domain and range. Foundation for calculus and Class 12 algebra.

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