# Recent activity

1
A simple graph is one in which there are no self-loops and each pair of distinct vertices is connected by at most one edge. Let $G$ be a simple graph on $8$ vertices such that there is a vertex of degree $1$, a vertex of degree $2$, a vertex of degree $3$, a vertex of degree ... of degree $6$ and a vertex of degree $7$. Which of the following can be the degree of the last vertex? $3$ $0$ $5$ $4$
2
In a database system, unique timestamps are assigned to each transaction using Lamport's logical clock. Let $TS(T_{1})$ and $TS(T_{2})$ be the timestamps of transactions $T_{1}$ and $T_{2}$ respectively. Besides, $T_{1}$ holds a lock on the ... , but not starvation-free. The database system is starvation-free, but not deadlock-free. The database system is neither deadlock-free nor starvation-free.
1 vote
3
What is the complement of the language accepted by the NFA shown below? $\not{O}$ $\{\epsilon\}$ $a^*$ $\{a,\epsilon\}$ $1$ $2$ $3$ $4$
4
Various parameter passing mechanisms have been in used in different programming languages. Which of the following statements is true? Call by value result is used in language Ada. Call by value result is the same as call by name. Call by value is the most robust. Call by reference is the same as call by name. Call by name is the most efficient.
5
Consider the following grammar $G$ with terminals $\{[, ]\}$, start symbol $S$, and non-terminals $\{A, B, C\}$: $S \rightarrow AC \mid SS \mid AB$ $C \rightarrow SB$ $A \rightarrow [$ $B \rightarrow ]$ A language $L$ ... context free $L(G)$ is infinite $L(G)$ can be recognized by a deterministic push down automaton $L(G)$ is prefix-closed $L(G)$ is recursive
6
Let $n \geq 2$ be any integer. Which of the following statements is not necessarily true? $\begin{pmatrix} n \\ i \end{pmatrix} = \begin{pmatrix} n-1 \\ i \end{pmatrix} + \begin{pmatrix} n-1 \\ i-1 \end{pmatrix}, \text{ where } 1 \leq i \leq n-1$ $n!$ divides the product of any $n$ ... $i \in \{1, 2, \dots , n-1\}$ If $n$ is an odd prime, then $n$ divides $2^{n-1} -1$
7
Let $L$ be a context-free language generated by the context-free grammar $G = (V, \Sigma, R, S)$ where $V$ is the finite set of variables, $\Sigma$ the finite set of terminals (disjoints from $V$), $R$ the finite set of rules and $S \in V$ the start variable. Consider the context-free grammar ${G}'$ ... ${L}'=LL$ ${L}'=L$ ${L}'=L^{\ast }$ ${L}'=\left \{ xx \mid x \in L \right \}$ None of the above
8
Consider the context-free grammar below ($\epsilon$ denotes the empty string, alphabet is $\{a,b\}$): $S\rightarrow \epsilon \mid aSb \mid bSa \mid SS.$ What language does it generate? $(ab)^{\ast} + (ba)^{\ast}$ $(abba) {\ast} + (baab)^{\ast}$ $(aabb)^{\ast} + (bbaa)^{\ast}$ Strings of the form $a^{n}b^{n}$ or $b^{n}a^{n},n$ any positive integer Strings with equal numbers of $a$ and $b$
9
A particular Panini-Backus-Naur Form definition for a $<\textsf{word}>$ is given by the following rules: $<\textsf{word}>:: = \:<\text{letter}> \mid <\text{letter}>\:<\text{pairlet}>\mid <\text{letter}>\:<\text{pairdig}>$ ... $I,II\:\text{or}\:III$ $I$ and $II$ only $I$ and $III$ only $II$ and $III$ only $I,II$ and $III$
10
A $\textit{clamp}$ gate is an analog gate parametrized by two real numbers $a$ and $b$, and denoted as $\text{clamp}_{a,b}$. It takes as input two non-negative real numbers $x$ and $y$ ... $y$ outputs the maximum of $x$ and $y?$ $1$ $2$ $3$ $4$ No circuit composed only of clamp gates can compute the max function
11
Consider the blocked-set semaphore where the signaling process awakens any one of the suspended process; i.e., Wait (S): If $S>0$ then $S\leftarrow S - 1$, else suspend the execution of this process. Signal (S): If there are processes that have been ... achieves mutual exclusion, but allows starvation for any $N\geq 2$ The program achieves mutual exclusion and starvation freedom for any $N\geq 1$
12
Consider a basic block: x:= a[i]; a[j]:= y; z:= a[j] optimized by removing common sub expression a[i] as follows: x:= a[i]; z:= x; a[j]:= y. Which of the following is true? Both are equivalent. The values computed by both are exactly the ... exactly the same values only if $i$ is not equal to $j$. They will be equivalent in concurrent programming languages with shared memory. None of the above.
13
Consider the following solution (expressed in Dijkstra's guarded command notation) to the mutual exclusion problem. process P1 is begin loop Non_critical_section; while not (Turn=1) do skip od; Critical_section_1; Turn:=2; end loop end process P2 is begin loop Non_critical_section; while not ... and (3), but does not satisfies the requirement (2). Satisfies all the requirement (1), (2), and (3).
14
Assume a demand paged memory system where ONLY THREE pages can reside in the memory at a time. The following sequence gives the order in which the program references the pages. $1, 3, 1, 3, 4, 2, 2, 4$ Assume that least frequently used page is replaced when necessary. If ... , respectively $1,1,1,2$ times, respectively $1,1,1,1$ times, respectively $2,1,2,2$ times, respectively None of the above
15
Suppose $n$ straight lines are drawn on a plane. When these lines are removed, the plane falls apart into several connected components called regions. $A$ region $R$ is said to be convex if it has the following property: whenever two points are in $R$, then the ... regions are produced, but they need not all be convex. All regions are convex but there may be exponentially many of them.
16
Suppose there are $n$ guests at a party (and no hosts). As the night progresses, the guests meet each other and shake hands. The same pair of guests might shake hands multiple times. for some parties stretch late into the night , and it is hard to keep track.Still, they don't shake hands with ... $2 \mid \text{Even} \mid - \mid \text{Odd} \mid$ $2 \mid \text{Odd} \mid - \mid \text{Even} \mid$
17
Which of the following is NOT necessarily true? { Notation: The symbol ''$\neg$''notes negation; $P (x, y)$ means that for given $x$ and $y$, the property $P(x, y)$ is true }. $(∀x∀y P(x, y)) \Rightarrow (∀y∀x P(x, y))$ $(∀x∃y \neg P(x, y)) \Rightarrow \neg (∃x∀y P(x, y))$ ... $(∃x∀y P(x, y)) \Rightarrow (∀y∃x P(x, y))$ $(∀x∃y P(x, y)) \Rightarrow (∃y∀x P(x, y))$
18
Three candidates, Amar, Birendra and Chanchal stand for the local election. Opinion polls are conducted and show that fraction $a$ of the voters prefer Amar to Birendra, fraction $b$ prefer Birendra to Chanchal and fraction $c$ ... $(a, b, c) = (0.49, 0.49, 0.49);$ None of the above.
19
The function $f (x) = 2.5 \log_e \left( 2 + \exp \left( x^2 - 4x + 5 \right)\right)$ attains a minimum at $x =$? $0$ $1$ $2$ $3$ $4$
1 vote
20
A function $f: \mathbb{R} \rightarrow \mathbb{R}$ is said to be $\textit{convex}$ if for all $x,y \in \mathbb{R}$ and $\lambda$ such that $0 \leq \lambda \leq1,$ $f(\lambda x+ (1-\lambda)y) \leq \lambda f (x) + (1-\lambda) f(y)$. Let $f:$\mathbb{R}→ ... $p,q$ and $r$ must be convex? Only $p$ Only $q$ Only $r$ Only $p$ and $r$ Only $q$ and $r$
21
Suppose that $f(x)$ is a continuous function such that $0.4 \leq f(x) \leq 0.6$ for $0 \leq x \leq 1$. Which of the following is always true? $f(0.5) = 0.5$. There exists $x$ between $0$ and $1$ such that $f(x) = 0.8x$. There exists $x$ between $0$ and $0.5$ such that $f(x) = x$. $f(0.5) > 0.5$. None of the above statements are always true.
22
Consider directed graphs on $n$ labelled vertices $\{1,2, \dots ,n\}$, where each vertex has exactly one edge coming in and exactly one edge going out. We allow self-loops. How many graphs have exactly two cycles ? $\displaystyle \sum_{k=1}^{n-1} k!(n-k)!$ ... $n!\bigg[\displaystyle \sum_{k=1}^{n-1} \frac{1}{k}\bigg]$ $\frac{n!(n-1)}{2}$ None of the above
23
Which of the following graphs are bipartite? Only $(1)$ Only $(2)$ Only $(2)$ and $(3)$ None of $(1),(2),(3)$ All of $(1),(2),(3)$
24
Q.1 VAS = 46 bit , Page size = 4KB , Page table entry = 4B ,3 level paging used ,1st level =12bits, 2nd level = 12bits,3rd level=10 bits(from right to left) Page table size for 4MB process.?? Q.2 Program size = 32MB , Page size = 1KB, VAS=46 bit ,Page table entry = 4B 3 level paging 1st = 12 bit ,2nd = 12 bit , 3rd = 10 bit Page table size.??
25
if the order of the leaf node of a b+ tree is 3.where order of this leaf node represents the maximum number of (key,record ptr ) pair present in it then what is the minimum number of key possible in that leaf node? a)1 b)2
26
Let $G$ be a connected bipartite simple graph (i.e., no parallel edges) with distinct edge weights. Which of the following statements on $\text{MST}$ (minimum spanning tree) need $\text{NOT}$ be true? $G$ has a unique $\text{MST}$. Every $\text{MST}$ in $G$ ... the second lightest edge. Every $\text{MST}$ in $G$ contains the third lightest edge. No $\text{MST}$ in $G$ contains the heaviest edge.
1 vote
27
after BCA I wasted 1 year due to carelessness and another 1 year in MCA entrance preparation. After failing to get MCA seat in a good college enrolled in state university MCA degree. After MCA, spending almost 7 months in job search in 2015 to 2016, finally ... for a entry-level developer interview my confidence level is much low that I will be requiring to prepare dedicatedly for 3-4 weeks.
28
A group of N stations share a 56-kbps pure ALOHA channel. Each station outputs a 1000-bit frame on average once every 100 sec, even if the previous one has not yet been sent (e.g., the stations can buffer outgoing frames). What is the maximum value of N?
29
I'm in MCA 2nd year want to preparing for GATE 2020 ,but I've to attend classes and in the side of programming i don't know any technology or competitive programming i also want to pursue these two things too(In case I'll fail in GATE, as a backup plan for job) should i pursue CP or learn new technologies or leave them for GATE.? Please help me I'm in dilemma. Thank You.