Question

If set A contains four elements and set B contains five elements, then the number of one-one and onto mapping from A → B is ______.

विकल्प

• 120

• 0

• 720

• 20

Answer 1

If set A contains four elements and set B contains five elements, then the number of one-one and onto mapping from A → B is 0.

Explanation:

• Rule for Onto Functions: For a function to be onto, the number of elements in the domain (Set A) must be greater than or equal to the number of elements in the codomain (Set B).
• The Problem: Here, Set A has 4 elements and Set B has 5 elements (n(A) < n(B)).
• Conclusion: Since there aren't enough elements in A to cover all elements in B, no onto mapping is possible, making the total number 0.