Let A = {1, 2, 3,..., 10} and R = {(x, y) : x + 2y = 10, x, y ∈ A} be a relation on A. Then, R-1 =
1
{(2, 4), (4, 3), (6, 2), (8, 1)}
2
{(4, 2), (3, 4), (2, 6), (1, 8)}
3
{(4, 2), (3, 4), (2, 6)}
4
{(x, y) : 2x + y = 10, x, y ∈ A}
Let A = {1, 2, 3,..., 10} and R = {(x, y) : x + 2y = 10, x, y ∈ A} be a relation on A. Then, R-1 =