A = {3, 4}, B = {4, 5} and C = {5, 6}

B × C = {(4, 5), (4, 6), (5, 5), (5, 6)}

A × (B × C) = {(3, 4, 5), (3, 4, 6), (3, 5, 5), (3, 5, 6), (4, 4, 5), (4, 4, 6), (4, 5, 5), (4, 5, 6)}