If A = {1, 4, 9}, B = {1, 2, 3} and C = {1, 3, 5}, find A ∩ (B ∩ C).
B ∩ C = { 1, 3}
A ∩ (B ∩ C) = {1, 4, 9} ∩ {1,3}
= {1}