Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Relations and Functions

Question:

If R be a relation < from A = {1, 2, 3, 4} to B = {1, 3, 5} i.e. (a, b) ∈ R iff a<b, then RoR–1 is

Options:

{(1, 3), (1, 5), (2, 3), (2, 5), (3, 5), (4, 5)}

{(3, 1), (5, 1), (3, 2), (5, 2), (5, 3), (5, 4)}

{(3, 3), (3, 5), (5, 3), (5, 5)}

{(3, 3), (3, 4), (4, 5)}

Correct Answer:

{(3, 3), (3, 5), (5, 3), (5, 5)}

Explanation:

We have R = {(1, 3), (1, 5), (2, 3), (2, 5), (3, 5), (4, 5)}

∴ R–1 = {(3, 1), (5, 1), (3, 2), (5, 2), (5, 3), (5, 4)}

hence ROR–1 = {(3, 3), (3, 5), (5, 3), (5, 5)}

Hence (3) is the correct answer.