(i) Let us assume, A = {1, 2, 3, 4}

And, B = {x: x is a natural number and 4 x 6}

= {4, 5, 6}

∴

Hence, A and B are not disjoint.

(ii) Let us assume, A = {a, e, i, o, u}

And, B = {c, d, e, f}

∴

Hence, A and B are disjoint

(iii) Let us assume, A = {x: x is an even integer}

And, B = {x: x is an odd integer}

∴

Hence, A and B are disjoint