Let A={1,2,{3,4},5}. Which of the following statement are incorrect and why?
{{3,4}}`sub` A

Explanation

(i) False because {3, 4} is not a subset of A
(ii) True, because {3, 4} is an element of A
(iii) `because {3,4} in A, :. {{3,4}} sub A` is true
(iv) True, because 1 is an element of A
(v) False, because 1 is an element
(vi) True, because each element of {1,2,5} is in set A
(vii) False, because `{1,2,5}` is not an element of A, therefore `{1,2,5} sub A`
(viii) False, because `{1,2,3}` is not a subset of A
(ix) False, because `phi cancel(in)A`
(x) True, because empty set is a subset of every set
(xi) False, because `{phi}` is not a subset of set A.