August 01, 2017
31. A data cube C, has n dimensions, and each dimension has exactly p distinct values in the base cuboid. Assume that there are no concept hierarchies associated with the dimensions. What is the maximum number of cells possible in the data cube, C?
(A) pn (B) p
(C) (2n-1)p+1 (D) (p+1)n
Answer: D
Explanation:
(a) What is the maximum number of cells possible in the base cuboid?
pn.
This is the maximum number of distinct tuples that you can form with p distinct values per dimensions.
(b) What is the minimum number of cells possible in the base cuboid?
p.
You need at least p tuples to contain p distinct values per dimension. In this case no tuple shares any value on any dimension.
(c) What is the minimum number of cells possible in the data cube, C?
(2n-1)×p+1.
The minimum number of cells is when each cuboid contains only p cells, except for the apex, which contains a single cell.
(d) What is the maximum number of cells possible (including both base cells and aggregate cells) in the data cube, C?
(p+1)n.
The argument is similar to that of part (a), but now we have p+1 because in addition to the p distinct values of each dimension we can also choose ∗.
32. Suppose that from given statistics, it is known that meningitis causes stiff neck 50% of the time, that the proportion of persons having meningitis is 1/50000, and that the proportion of people having stiff neck is 1/20. Then the percentage of people who had meningitis and complain about stiff neck is:
(A) 0.01% (B) 0.02%
(C) 0.04% (D) 0.05%
Answer: B
Explanation:
The computation is based on the simplified Bayes’ formula.
P{B|A} = (P{A|B}·P{B) / P{A}.
P{M|S} = probability that a person had meningitis, conditioned by the existence of stiff neck.
P{S|M} = probability that a person complains about stiff neck, conditioned by the existence of meningitis. = 50%=1/2
P{S} = proportion of people who complain about stiff neck. = 1/20
P{M} = proportion of people who had meningitis. = 1/50,000
Then:
P{M|S} = (P{S|M}·P{M}) / P{S} =(1/2 x 1/50,000) / 1/20 = 0.0002 = 0.02%
33. ................. system is market oriented and is used for data analysis by knowledge workers including Managers, Executives and Analysts.
(A) OLTP (B) OLAP
(C) Data System (D) Market System
Answer: B
34. .................. allows selection of the relevant information necessary for the data warehouse.
(A) The Top-Down View (B) Data Warehouse View
(C) Data source View (D) Business Query View
Answer: A
35. The hash function used in double hashing is of the form:
(A) h(k, i)=(h1(k)+h2(k)+i)mod m (B) h(k, i)=(h1(k)+h2(k)-i)mod m
(C) h(k, i)=(h1(k)+ih2(k))mod m (D) h(k, i)=(h1(k)-ih2(k))mod m
Answer: C
36. In the following graph, discovery time stamps and finishing time stamps of Depth First Search (DFS) are shown as x/y where x is discovery time stamp and y is finishing time stamp.
It shows which of the following depth first forest?
(A) {a,b,e} {c,d,f,g,h} (B) {a,b,e} {c,d,h} {f,g}
(C) {a,b,e} {f,g} {c,d} {h} (D) {a,b,c,d} {e,f,g} {h}
Answer: A
37. The number of disk pages access in B-tree search, where h is height, n is the number of keys, and t is the minimum degree, is:
(A) θ(logn h*t) (B) θ(logt n*h)
(C) θ(logh n) (D) θ(logt n)
Answer: D
38. The inorder traversal of the following tree is:
(A) 2 3 4 6 7 13 15 17 18 18 20
(B) 20 18 18 17 15 13 7 6 4 3 2
(C) 15 13 20 4 7 17 18 2 3 6 18
(D) 2 4 3 13 7 6 15 17 20 18 18
Answer: D
39. An ideal sort is an in-place-sort whose additional space requirement is ...............
(A) O(log2n) (B) O(nlog2n)
(C) O(1) (D) O(n)
Answer: C
40. Which of the following is not a congestion policy at network layer?
(A) Flow Control Policy
(B) Packet Discard Policy
(C) Packet Lifetime Management Policy
(D) Routing Algorithm
Answer: A
41. Loop unrolling is a code optimization technique:
(A) that avoids tests at every iteration of the loop
(B) that improves performance by decreasing the number of instructions in a basic block.
(C) that exchanges inner loops with outer loops
(D) that reorders operations to allow multiple computations to happen in parallel.
Answer: A
42. What will be the hexadecimal value in the register ax (32-bit) after executing the following instructions?
Mov al, 15
Mov ah, 15
Xor al, al
Mov cl, 3
Shr ax, cl
Codes:
(A) 0F00 h (B) 0F0F h
(C) 01E0 h (D) FFFF h
Answer: C
43. Which of the following statements is false?
(A) Top-down parsers are LL parsers where first L stands for left-to-right scan and second L stands for a leftmost derivation.
(B) (000)* is a regular expression that matches only strings containing an odd number of zeroes, including the empty string.
(C) Bottom-up parsers are in the LR family, where L stands for left-to-right scan and R stands for rightmost derivation
(D) The class of context-free languages is closed under reversal. That is, if L is any context-free language, then the language LR={WR:wϵL} is context free.
Answer: B
44. System calls are usually invoked by using:
(A) A privileged instruction (B) An indirect jump
(C) A software interrupt (D) Polling
Answer: C
45. The ............... transfers the executable image of a C++ program from hard disk to main memory.
(A) Compiler (B) Linker
(C) Debugger (D) Loader
Answer: D
46. In software testing, how the error, fault and failure are related to each other?
(A) Error leads to failure but fault is not related to error and failure
(B) Fault leads to failure but error is not related to fault and failure
(C) Error leads to fault and fault leads to failure
(D) Fault leads to error and error leads to failure
Answer: C
47. Which of the following is not a software process model?
(A) Prototyping (B) Iterative
(C) Timeboxing (D) Glassboxing
Answer: D
48. How many solutions are there for the equation x+y+z+u=29 subject to the constraints that x≥1, y≥2, z≥3 and u≥0?
(A) 4960 (B) 2600
(C) 23751 (D) 8855
Answer: B
Explanation:
We let y1=x-1, y2=y-2, y3=z-3, y4=u-0
We count the number of solutions for y1+y2+y3+y4=29-6=23
n=4, r=23
The number of solutions is C(n+r-1, r) = C(4+23-1, 23)
= C(26,23) = C(26,3) = 26x25x24/1x2x3 = 2600
Explanation:
We let y1=x-1, y2=y-2, y3=z-3, y4=u-0
We count the number of solutions for y1+y2+y3+y4=29-6=23
n=4, r=23
The number of solutions is C(n+r-1, r) = C(4+23-1, 23)
= C(26,23) = C(26,3) = 26x25x24/1x2x3 = 2600
49. A unix file system has 1-KB blocks and 4-byte disk addresses. What is the maximum file size if i-nodes contain 10 direct entries and one single, double and triple indirect entry each?
(A) 32 GB (B) 64 GB
(C) 16 GB (D) 1 GB
Answer: C
Explanation:
block = 210
block pointer size = 4B
entries possible in block = 210/22 = 256
direct pointer gives = 10 * 256 = 10 blocks
single indirect gives = 256 * 256 = 28 blocks
double indirect gives = 256 * 256 * 256 = 216 blocks
triple indirect gives = 256 * 256 * 256 * 256 = 224 blocks
total = 10 blocks + 28 blocks + 216 blocks + 224 blocks
= 16843018 blocks = 16843018 * 1024 = 17247250432 ≈ 16 GB
50. ................. uses electronic means to transfer funds directly from one account to another rather than by cheque or cash?
(A) M-Banking (B) E-Banking
(C) O-Banking (D) C-Banking
Answer: B
