Q.

Let A = {1, 2, 3, ..........., 100}. Let R be a relation on A defined by (x, y) ∈ R if and only if 2x = 3y. Let R1 be a symmetric relation on A such that RR1 and the number of elements in R1 is n. Then, the minimum value of n is ______.            [2024]

 


Ans.

(66)

We have, A = {1, 2, 3, ..., 100}

R = {(3, 2), (6, 4), (9, 6), (12, 8), ....(99, 66)}

n(R) = 33

Since, R1 is symmetric and RR1

∴ n(R1) = 66