# Hughes Software systems Paper

**Hughes Software systems**

The Questions are follows

1. Number of null pointers in any binary tree = n+1^M

2. max(t1,t2,…tn) = pipelining^M

3. 50% -DBETXXXXXX – density^M

1) find the probability of getting a number with 7 between 100 and

999 (both inclusive).

ans:

FreshersHome.com

2) There are 10 items in a box, out of which 3 are defective.

2 balls are taken one after the other. what is the probability

that both of them are defective?

Ans: 1/15 or 6/90

3) Context free grammar is accepted by

a) finite automata

b)push down automata

c) two way bounded automata

d) both b and c

4) which is not a memory management scheme?

a) buddy system

b) swapping

c) monitors

d) paging Ans : c

5) qn. on karnaugh map for simplifying boolean expressions

– 1 1 –

1 – – 1

1 – – 1

– 1 1 –

karnaugh map

6) qn. on nand gates .

7) context sensitive grammar

8) An identifier can start with a letter followed by any number of

>letter

or digits .

ans: L.(LUD)*

9) 8MB total memory, 256 k cache , 4k is block size. direct mapping

how many different physical memory blocks can be mapped on to the

>cache.

a) 64 b) 256 c) 128

10) CSMA/CD is used in

a) token ring

b) FDDI

d) Ethernet

Ans : d

11) In TCP/IP header , checksum contains

a) sum of all the words

b) ones complement of the data

c) ones complement of the sum of all the words

d) ones complement of the sum in ones complement

Ans : d

12) Max no of Acknowledgments for a 4 bit sequence number in a

sliding window protocol.

13) which is a good way of representing variables in recursion

a) local variables

b) static variables

c) global variables

d)

14) c programs

func() {

static int i = 10;

printf(“%d”,i);

i++;

}

what is the value of i if the function is called twice ?

Ans : 11

15) Qn. on pointers .

16) given page table,page size and offset find the corresponding

physical address ?

ans : a (3*1024+576) (pageno*pagesize+offset)

17) In a memory chip 4k size and 16bit words to be stored. No of

address and data lines reqd.

Ans) 16 data and 12 address

18) idetify in which pass of the 2 pass compiler

1) literals

2) address resolution

3) listing

4)

19) object code not requires

a) relocation bits

b) external names and place where they are located

c) absolute address

d) all the object codes

20) ARP

a) MAC to IP

b) IP to MAC

c)

Ans : b

21) Qn on Balanced tree ? A balanced tree is given and a node is

>added

at the leaf and asked to find the no of unbalanced nodes?

22) order of Hashing time

a) 0(1)

b) 0(n2)

4) parse tree

s -> s + s ; s -> s * s ; s -> a

find the no of parse trees for a+a*a+a

a) 4

b) 5

c) 6

ans: 5

25) order of deleting an node from a linked list. (pointer is to an

arbitrary node)

a)0(1)

b)0(n)

26) A chocolate of size nXn is given and is to be made into pices of

>size

1×1. At a time both horizontal and a vertical cut is done. Find the

order of complexity

a) 0(n2)

b) o(nlogn)

c) o(logn)

Ans : a

27) A directed graph is represented by adjacency list. To find the

complexity of indegree of the node. e – edge n- vertices’s

a) o(e+n)

28) No of leaf nodes given. find the no of nodes with degree 2.

29) AX = B . A is mXn and B is mX1 and several options given like

a) there is a unique solution if rank of A is same as rank of

augmented matrix [A b]

b) there are multiple solutions

30) LXI sp,2099h

LXI b, 2012h

push b

31) Which of the following are false (on complexities)

32) A,B are sets. A’s cardinality is m and B’s is n where m < n

how many one to one mappings can be obtained.

a) n ^ m

b) npm

c) mpn

d) mcn

33) In scheduling algorithms which are logically executed but suspended

a) preemptive

b) SJF

c)non preemptive

d) all the above

Ans : a

34) I/O redirection is

a) copying programs files through a pipe

b) input files are created

c) input file taken from existing ones

d) none

35) symmetric multiprocessing can be done in

a) snoopy protocols

b) cache coherence

36) dining philosophers problems to avoid dead locke

a) 1 person will take left one and all other will take right one

b) adjacent persons should not eat concurrently

37) for converting infix expression to postfix what

do we require

a) operand stack

b) operator stack

c)

38) 0 is represented as both and negative and positive

a) ones complement

b) twos complement

c) two’s complement has extra negative number

39) Difference between c and c++?

a)In c++ we can define variables in the middle

b)dynamic scoping

40) Which of the following is correct

a) Synchronous transmission needs more bandwidth than Asynchronous.

b) Ina synchronous transmission , the time is associated with data