1) B ∩ C = {k}.
2) B ∩ D = {n}.
3) B ∪ C ∪ D = {h, o, y, ch, k, n, e, a, i}.
4) B ∩ (C ∩ D) = {} (пустое множество).
5) (B ∩ C) ∪ (C ∩ D) = {k, e}.
6) (B ∩ C) ∪ (B ∩ D) = {k, n}.
7) (B ∩ C) ∪ (B ∩ D) ∪ (C ∩ D) = {k, n, e}.
8) (B ∩ C) ∪ ((B ∩ D) ∩ (C ∩ D)) = {k, n}.