Let R be a relation from A = {1, 2, 3, 4} to B = {1, 3, 5} such that
R = {(a, b) : a < b, where a ∈ A and b ∈ B}.
What is RoR-1 equal to?
1
{(1, 3), (1, 5), (2, 3), (2, 5), (3, 5), (4, 5)}
2
{(3, 1), (5, 1), (3, 2), (5, 2), (5, 3), (5, 4)}
3
{(3, 3), (3, 5), (5, 3), (5, 5)}
4
{(3, 3), (3, 4), (4, 5)}