# Recent activity by Nikhil_dhama

1
For constants $a \geq 1$ and $b>1$, consider the following recurrence defined on the non-negative integers: $T(n) = a \cdot T \left(\dfrac{n}{b} \right) + f(n)$ Which one of the following options is correct about the recurrence $T(n)$? If $f(n)$ is $n \log_2(n)$, then $T(n)$ ... $\Theta(n^{\log_b(a)})$ If $f(n)$ is $\Theta(n^{\log_b(a)})$, then $T(n)$ is $\Theta(n^{\log_b(a)})$
2
Let $\langle M \rangle$ denote an encoding of an automaton $M$. Suppose that $\Sigma = \{0,1\}$. Which of the following languages is/are $\text{NOT}$ recursive? $L= \{ \langle M \rangle \mid M$ is a $\text{DFA}$ such that $L(M)=\emptyset \}$ $L= \{ \langle M \rangle \mid M$ is ... $L(M)=\emptyset \}$ $L= \{ \langle M \rangle \mid M$ is a $\text{PDA}$ such that $L(M)=\Sigma ^* \}$
3
A circular sheet of paper is folded along the lines in the direction shown. The paper, after being punched in the final folded state as shown and unfolded in the reverse order of folding, will look like _______.
4
Consider the following recurrence relation. $T\left ( n \right )=\left\{\begin{array} {lcl} T(n/2)+T(2n/5)+7n & \text{if} \; n>0\\1 & \text{if}\; n=0 \end{array}\right.$ Which one of the following options is correct? $T(n)=\Theta (n^{5/2})$ $T(n)=\Theta (n\log n)$ $T(n)=\Theta (n)$ $T(n)=\Theta ((\log n)^{5/2})$
5
Consider the following greedy algorithm for colouring an $n$-vertex undirected graph $G$ with colours $c_{1}, c_{2}, \dots:$ consider the vertices of $G$ in any sequence and assign the chosen vertex the first colour that has not already been assigned to any of its neighbours. Let $m(n, r)$ be the minimum ... $m\left ( n, r \right ) = nr$ $m\left ( n, r \right ) = n\binom{r}{2}$
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Let $A$ be a $3 \times 6$ matrix with real-valued entries. Matrix $A$ has rank $3$. We construct a graph with $6$ vertices where each vertex represents distinct column in $A$, and there is an edge between two vertices if the two columns represented by the vertices are ... The graph is connected. There is a clique of size $3$. The graph has a cycle of length $4$. The graph is $3$-colourable.
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Let $G$ be an undirected graph. For any two vertices $u, v$ in $G$, let $\textrm{cut} (u, v)$ be the minimum number of edges that should be deleted from $G$ so that there is no path between $u$ and $v$ in the resulting graph. Let $a, b, c, d$ be $4$ vertices in $G$. Which of the following ... $\textrm{cut} (c,d) = 2$ $\textrm{cut} (b,d) = 2$, $\textrm{cut} (b,c) = 2$ and $\textrm{cut} (c,d) = 1$
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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? $G$ hasa unique $\text{MST}$. Every $\text{MST}$ in $G$ ... second lightest edge. Every $\text{MST}$ in $G$ contains the third lightest edge. No $\text{MST}$ in $G$ contains the heaviest edge.
9
Consider the following statements about propositional formulas. $\left ( p\wedge q \right )\rightarrow r$ and $\left ( p \rightarrow r \right )\wedge \left ( q\rightarrow r \right )$ are $\textit{not }$ ... Depending on the values $p$ and $q$, $\text{(i)}$ can be either true or false, while $\text{(ii)}$ is always false.
10
Five married couples attended a party. In the party, each person shook hands with those they did not know. Everyone knows his or her spouse. At the end of the party, Shyamal, one of the attendees, listed the number of hands that other attendees including his spouse shook. He ... $8$ once in the list. How many persons shook hands with Shyamal at the party? $2$ $4$ $6$ $8$ Insufficient information
11
Fix $n\geq 6$. Consider the set $\mathcal{C}$ of binary strings $x_{1}, x_{2} \dots x_{n}$ of length $n$ such that the bits satisfy the following set of equalities, all modulo $2$: $x_{i}+x_{i+1}+x_{i+2}=0$ for all $1\leq i\leq n-2, x_{n-1}+x_{n}+x_{1}=0,$ ... $3$ $\left | \mathcal{C} \right |=4$. If $n\geq 6$ is not divisible by $3$ then $\left | \mathcal{C} \right |=1$.
12
A matching in a graph is a set of edges such that no two edges in the set share a common vertex. Let $G$ be a graph on $n$ $\textit{vertices}$ in which there is a subset $M$ of $m$ $\textit{edges}$ which is a matching. Consider a random process where each vertex in the graph is independently selected ... $p^{2m}$ $\left ( 1-p^{2} \right )^{m}$ $1-\left ( 1-p\left ( 1-p \right ) \right )^{m}$
13
What is the worst-case number of arithmetic operations performed by recursive binary search on a sorted array of size $n$? $\Theta ( \sqrt{n})$ $\Theta (\log _2(n))$ $\Theta(n^2)$ $\Theta(n)$
14
For a statement $S$ in a program, in the context of liveness analysis, the following sets are defined: $\text{USE(S)}$ : the set of variables used in $S$ $\text{IN(S)}$ : the set of variables that are live at the entry of $S$ $\text{OUT(S)}$ : the set of variables that are live at the exit ... $) }\cup \text{ OUT ($S_2$)}$ $\text{OUT ($S_1$)}$ = $\text{USE ($S_1$)} \cup \text{IN ($S_2$)}$
15
In an examination, a student can choose the order in which two questions ($\textsf{QuesA}$ and $\textsf{QuesB}$) must be attempted. If the first question is answered wrong, the student gets zero marks. If the first question is answered correctly and the second question ... and then $\textsf{QuesA}$. Expected marks $22$. First $\textsf{QuesA}$ and then $\textsf{QuesB}$. Expected marks $16$.
16
Suppose that $f: \mathbb{R} \rightarrow \mathbb{R}$ is a continuous function on the interval $[-3, 3]$ and a differentiable function in the interval $(-3,3)$ such that for every $x$ in the interval, $f’(x) \leq 2$. If $f(-3)=7$, then $f(3)$ is at most __________
17
Suppose that $P$ is a $4 \times 5$ matrix such that every solution of the equation $\text{Px=0}$ is a scalar multiple of $\begin{bmatrix} 2 & 5 & 4 &3 & 1 \end{bmatrix}^T$. The rank of $P$ is __________
18
Consider a set-associative cache of size $\text{2KB (1KB} =2^{10}$ bytes$\text{)}$ with cache block size of $64$ bytes. Assume that the cache is byte-addressable and a $32$ -bit address is used for accessing the cache. If the width of the tag field is $22$ bits, the associativity of the cache is _________
19
Consider the three-way handshake mechanism followed during $\text{TCP}$ connection establishment between hosts $P$ and $Q$. Let $X$ and $Y$ be two random $32$-bit starting sequence numbers chosen by $P$ and $Q$ respectively. Suppose $P$ sends a $\text{TCP}$ connection request message to $Q$ with a ... $\text{SEQ}$ number $=Y$, $\text{ACK}$ bit $=1$, $\text{ACK}$ number $=X$, $\text{FIN}$ bit $=0$
20
Which one of the following circuits implements the Boolean function given below? $f(x,y,z) = m_0+m_1+m_3+m_4+m_5+m_6$, where $m_i$ is the $i^{\text{th}}$ minterm.
21
The number of units of a product sold in three different years and the respective net profits are presented in the figure above. The cost/unit in Year $3$ was Re. $1$, which was half the cost/unit in Year $2$. The cost/unit in Year $3$ was one-third of the cost/unit in Year $1$. ... The ratio of the selling price in Year $2$ to the selling price in Year $3$ is _________. $4:3$ $1:1$ $3:4$ $1:2$
22
The number of students in three classes is in the ratio $3:13:6$. If $18$ students are added to each class, the ratio changes to $15:35:21$. The total number of students in all the three classes in the beginning was: $22$ $66$ $88$ $110$
23
Three processes arrive at time zero with $\text{CPU}$ bursts of $16,\;20$ and $10$ milliseconds. If the scheduler has prior knowledge about the length of the $\text{CPU}$ bursts, the minimum achievable average waiting time for these three processes in a non-preemptive scheduler (rounded to nearest integer) is _____________ milliseconds.
24
Assume that a $12$-bit Hamming codeword consisting of $8$-bit data and $4$ check bits is $d_8d_7d_6d_5c_8d_4d_4d_3d_2c_4d_1c_2c_1$ ... $0$ $x$ is $0$ and $y$ is $1$ $x$ is $1$ and $y$ is $0$ $x$ is $1$ and $y$ is $1$
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Given below are two statements $1$ and $2$, and two conclusions $\text{I}$ and $\text{II}$ $\text{Statement 1:}$ All bacteria are microorganisms. $\text{Statement 2:}$ All pathogens are microorganisms. $\text{Conclusion I:}$ ... is correct Either conclusion $\text{I}$ or $\text{II}$ is correct Neither conclusion $\text{I}$ nor $\text{II}$ is correct
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A bag has $r$ red balls and $b$ black balls. All balls are identical except for their colours. In a trial, a ball is randomly drawn from the bag, its colour is noted and the ball is placed back into the bag along with another ball of the same colour. Note that the number of balls in the bag will ...
A relation $R$ is said to be circular if $aRb$ and $bRc$ together imply $cRa$. Which of the following options is/are correct? If a relation $S$ is reflexive and symmetric, then $S$ is an equivalence relation. If a relation $S$ is circular and symmetric, ... and circular, then $S$ is an equivalence relation. If a relation $S$ is transitive and circular, then $S$ is an equivalence relation.
Consider a computer system with a byte-addressable primary memory of size $2^{32}$ bytes. Assume the computer system has a direct-mapped cache of size $\text{32 KB}$ ($\text{1 KB}$ = $2^{10}$ bytes), and each cache block is of size $64$ bytes. The size of the tag field is __________ bits.
A complete $n$-ary tree is one in which every node has $0$ or $n$ sons. If $x$ is the number of internal nodes of a complete $n$-ary tree, the number of leaves in it is given by $x(n-1) +1$ $xn-1$ $xn +1$ $x(n+1)$