(i) False. Each element of {a, b} is also an element of {b, c, a}.
(ii) True. a, e are two vowels of the English alphabet.
(iii) False. 2∈{1, 2, 3}; however, 2∉{1, 3, 5}
(iv) True. Each element of {a} is also an element of {a, b, c}.
(v) False. The elements of {a, b, c} are a, b, c. Therefore, {a}⊂{a, b, c}
(vi) True. {x:x is an even natural number less than 6} = {2, 4}
{x:x is a natural number which divides 36}= {1, 2, 3, 4, 6, 9, 12, 18, 36}