0 votes 0 votes second one is uncountable? abhishekmehta4u asked Sep 29, 2018 abhishekmehta4u 852 views answer comment Share Follow See all 22 Comments See all 22 22 Comments reply Show 19 previous comments Mk Utkarsh commented Oct 1, 2018 reply Follow Share different question. i can write a proof but still you'll not believe so what's the point 0 votes 0 votes Mk Utkarsh commented Oct 1, 2018 reply Follow Share variety of explanations for this question, https://www.quora.com/How-would-I-prove-the-set-of-numbers-that-are-powers-of-2-are-a-countably-infinite-set 0 votes 0 votes srestha commented Oct 3, 2018 reply Follow Share @Mk Utkharsh yes it will be countable as it is set of natural number ans given plz chk 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes All regular languages are countable sets of words. Finite languages are trivially countable. Infinite languages are countable because the corresponding DFA can be walked over, enumerating the entire language in an ordered manner, allowing all strings to be mapped to the natural numbers. So, Though powerset is not countable for all sets,but power set of Natural number and integer are countable Though if there are possibility of rational number , it will be uncountable infinite set So, here 1st one is finite set and 2nd one power set of Natural number, which are integer. So, both (i) and (ii) need to be countable Ref:https://stackoverflow.com/questions/52567805/can-countable-string-is-countable-always https://cs.stackexchange.com/questions/97914/is-countable-set-always-countable?noredirect=1#comment208658_97914 srestha answered Oct 3, 2018 srestha comment Share Follow See all 0 reply Please log in or register to add a comment.