(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. 2ϵ{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 element of {a,b,c} are a,b,c. Therefore, a⊂a,b,c
(vi) True. {x:xis an even natural number less than 6}={2,4}
{x:xis a natural number which divides 36}={1,2,3,4,6,9,12,18,36}
Here, {2,4}⊂{1,2,3,4,6,9,12,18,36}