# Questions by vishal8492

1
A cache is having 64KB capacity 128 byte lines and is 4-way set associative the sytem containing the cache uses 32 bit address. How many sets does the cache have ?
2
Okay , So R is RE , L is Regular language. 1) Definitely true , RE not closed under complement. 2) Regular union Non regular language ? Could be possbile. Not too sure. 3) L interesection R' is not RE ? Not sure 4) ?? Not sure 5) ?? Not sure Can you help with these ?
3
Number of states for DFA which is divisble by 8 , I mostly try to identify by using number of distinct states. In this case , it would be 8 ; but minimized dfa would be less ? I read somewhere , the unique states sould be 4 and so minimum states are 4. Can't ... exceprt now , but is this right ? And can someone explain , what is meant by unique states ? Do we have fixed formula for such problems ?
1 vote
4
Having hard time , to understand why (A) isn't the answer ? Looking at DFA it looks , 2* is good starting state ; then there are two paths 0 first path good enough ; for second path 1 is necessary what about 2 ; shouldn't it be 2* as it's 0 or more occurences. Am I solving it wrong ? Is this incorrect approach to look at the question ?
1 vote
5
So , 1 is mandatory in Regular expression ; and both of above grammar allows strings without 1 to be genearated. So , I expected None of above to be answer. What Am I missing here ? Consider for (A) Production = A0 -> A1 A1-> 0
6
I'm having problems with identifying CFL languages a lot recently.I understand L1 is not , but how come L2 is ? Understood 1 stack is enough but aren't there two comparisons ? Or that doesn't matter you can do any number of comparisons ? It's just number of stacks ... , 2 comparisons are needed n<k and k<2n. Any other fixed formula , to identify class of language which acts as easy guideline ?
7
It seemed like , this is textbook example of non-CFL language ; will require 2 comparisons . That means no complement exist was the answer , I was expecting. Why answer given is CFL , am I missing something ?
8
Isn't WxWr DCFL as X acts as marker so DCFL should be right choice , why is it categorized as CFL and not DCFL?
9
Let A be (3×3) real matrix. Suppose 1 & -1 are two of three Eigen values of A and 18 is one of the Eigen values of A2+3A. Then [ A ] A is invertible as well as A2 + 3A is invertible [ B ] A^2+3A is invertible but A is not invertible [ C ] A is invertible but A^2+3A is not invertible [ D ] Both A & A^2+3A are not invertible
10
I've been struggling to come to exact solution for this. Master's theorem is not applicable and likely way to get to answer is Recursion tree. Which is giving me Theta(n) as an answer. Steps : => 1) T(n) = 2T(n/4) + √3 2) Emerging Pattern => (1/2^k) * n 3) Considering ... + n/4 + ..... = n/2 Which is incorrect , Answer given is ( √n log n ) , would appreciate if someone could shed light how so ?
1 vote
11
Correct symbolical representation of statement => "All Birds are beautiful" ? Now , here the logical way to approach seems like necessary condition. Since All birds are beautiful , can be equivalent to , "If X is a bird then X is beautiful." Again , with Universal ... First , I'm totally lost now , with when to choose conjunction vs implication and how the above form is closer to sentential form.
12
(V(x) {Pink(x) ^ Building(x) -> Wonderful(x) } ) => Intuitively it seems like , (I) If building is pink then it is wonderful , but other form given is => (II) All pink buildings are wonderful. Seems fair enough , it'll encompass universal quantifier. But , If building ... form is e.g. ((x) {Pink(x) ^ Building(x) -> Wonderful(x) } ) without any quantifier ? Or both are valid transalations here ?
1 vote
13
I'm having hard time understanding how following series converges ; 1 + 2/5 + 3/5^2 + 4/5^3 + 5/5^4 + ............ infinity