ISRO CS 2018
Question 1 
The difference between a named pipe and a regular file in Unix is that
Unlike a regular file, named pipe is a special file  
The data in a pipe is transient, unlike the content of a regular file  
Pipes forbid random accessing, while regular files do allow this.  
All of the above 
Discuss it
Question 2 
A class of 30 students occupy a classroom containing 5 rows of seats, with 8 seats in each row. If the students seat themselves at random, the probability that the sixth seat in the fifth row will be empty is
1/5  
1/3  
1/4  
2/5 
Discuss it
Question 2 Explanation:
There are 5 rows with 8 seats in each row.
So, there are total 40 seats
If sixth seat in the fifth row is empty then 30 students have 39 choices of seats
So, ways to choose from given choices = ^{39}C_{30}
But, total ways to choose = ^{40}C_{30}
Probability = ^{39}C_{30} / ^{40}C_{30}
Probability = 1/4
Option (C) is correct.
Question 3 
The domain of the function log( log sin(x) ) is
0 < x < π  
2nπ < x < (2n + 1) π , for n in N  
Empty set  
None of the above

Discuss it
Question 4 
The following paradigm can be used to find the solution of the problem in minimum time:
Given a set of nonnegative integer, and a value K, determine if there is a subset of the given set with sum equal to K:
Divide and Conquer  
Dynamic Programming  
Greedy Algorithm  
Branch and Bound 
Discuss it
Question 4 Explanation:
Given problem is Subsetsum problem in which a set of nonnegative integers, and a value sum is given, to determine if there is a subset of the given set with sum equal to given sum. With recursion technique, time complexity of the above problem is exponential. We can solve the problem in Pseudopolynomial time using Dynamic programming.
Refer: Subset Sum Problem
Option (B) is correct
Question 5 
( G, *) is an abelian group. Then
x = x ^{1}, for any x belonging to G  
x = x^{2}, for any x belonging to G  
(x * y )^{2} = x^{2} * y^{2}, for any x, y belonging to G  
G is of finite order

Discuss it
Question 6 
Consider the following C code segment:
#includeFor the program fragment above, which of the following statements about the variables i and j must be true after execution of this program? [!(exclamation) sign denotes factorial in the answer]main() { int i, j , x ; scanf("%d", &x); i = 1 ; j = 1; while ( i< 10 ) { j = j * i; i = i + 1; if (i == x) break ; } }
( j = (x  1 )! ) ∧ (i >= x)  
( j = 9!) ∧ (i =10)  
(( j = 10!) ∧ (i = 10 )) V (( j = (x  1)!) ∧ (i = x ))  
(( j = 9!) ∧ (i = 10)) V (( j = (x  1)!) ∧ (i = x )) 
Discuss it
Question 7 
A computer uses ternary system instead of the traditional binary system. An n bit string in the binary system will occupy
3 + n ternary digits  
2n / 3 ternary digits  
n(log_{2}3) ternary digits  
n(log_{3}2 ) ternary digits 
Discuss it
Question 8 
Which of the following is application of Breath First Search on the graph?
Finding diameter of the graph  
Finding bipartite graph  
Both (a) and (b)  
None of the above 
Discuss it
Question 8 Explanation:
BFS is used to Find the diameter of the graph and to test whether a graph is bipartite or not. BFS has many other applications also.
Refer: Applications of Breadth First Traversal
Option (C) is correct.
Question 9 
Micro program is
the name of a source program in micro computers  
set of micro instructions that defines the individual operations in response to a machinelanguage instruction  
a primitive form of macros used in assembly language programming  
a very small segment of machine code 
Discuss it
Question 10 
Given two sorted list of size m and n respectively. The number of comparisons needed the worst case by the merge sort algorithm will be
m x n  
maximum of m and n  
minimum of m and n  
m + n  1 
Discuss it
Question 10 Explanation:
To merge two lists of size m and n, we need to do m+n1 comparisons in worst case. Since we need to merge 2 at a time, the optimal strategy would be to take smallest size lists first. The reason for picking smallest two items is to carry minimum items for repetition in merging.
So, option (D) is correct.
There are 79 questions to complete.