Let A = {1, 2, 3, 4}

Given:

A = {1, 2, 3, 4}

R = {(a, b) : a ∈ A, b ∈ A, a divides b}

We know:

1 divides 1, 2, 3 and 4.

2 divides 2 and 4.

3 divides 3.

4 divides 4.

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