3 votes 3 votes The number of elements in the power set of $\{\{1,2\},\{2,1,1\},\{2,1,1,2\}\}$ is $3$ $8$ $4$ $2$ Set Theory & Algebra isrodec2017 + – gatecse asked Dec 17, 2017 • recategorized Feb 11, 2018 by srestha gatecse 4.6k views answer comment Share Follow See 1 comment See all 1 1 comment reply Deepak Poonia commented Apr 19, 2023 reply Follow Share Question Maker in his mind: CriATivE A Dumb Question!! 1 votes 1 votes Please log in or register to add a comment.
Best answer 25 votes 25 votes Consider this: {1} & {1,1} are the same set. {Since, order & repetition of elements in the set won't make it a new set} Here, {1,2}, {2,1,1} & {2,1,1,2} are same & so the number of elements in A will be 1 Number of elements in Power-set(A) = 21 = 2 srivivek95 answered Dec 20, 2017 • selected Feb 12, 2018 by Prashant. srivivek95 comment Share Follow See all 7 Comments See all 7 7 Comments reply Show 4 previous comments Tuhin Dutta commented Apr 3, 2018 reply Follow Share @Registered user 7 8 should be the answer. 0 votes 0 votes Registered user 7 commented Apr 5, 2018 reply Follow Share why cannot 4?..2^2 as {1} is part of {1,2} 0 votes 0 votes Nymeria commented Apr 21, 2018 reply Follow Share {1} and {1,1} are same as a set cannot contain duplicates and hence {1,1}={1} and not because {1} is a part of {1,1}. 1 votes 1 votes Please log in or register to add a comment.
5 votes 5 votes no. of elements in power set of A = $2^{|A|}$ |A| = 3, therefore $|power-set(A)| = 2^{3} =8$ joshi_nitish answered Dec 20, 2017 joshi_nitish comment Share Follow See all 2 Comments See all 2 2 Comments reply Anu007 commented Dec 20, 2017 reply Follow Share isro says 2 0 votes 0 votes REGGIE S commented Dec 20, 2017 reply Follow Share How can it be two, no way.. 0 votes 0 votes Please log in or register to add a comment.
5 votes 5 votes If the given set is a multiset. Answer is 8. If it is a simple set. Answer is 2. Karan Saini answered Dec 20, 2017 Karan Saini comment Share Follow See 1 comment See all 1 1 comment reply bhanu kumar 1 commented Apr 10, 2018 reply Follow Share what about multi set and simple set ? ..explain....... 0 votes 0 votes Please log in or register to add a comment.