Mock Test 11 — Delhi Police Constable Full Pattern (100 MCQs)

This is a full-length practice test following the exact Delhi Police Constable written exam pattern: 25 Reasoning, 50 General Knowledge & Current Affairs, 15 Numerical Ability, and 10 Computer Knowledge questions.

Section A: Reasoning (Q1–25)

1. In the analogy "Nurse is to Hospital as Librarian is to ___," the missing word is:
   (a) Library (b) Book (c) Shelf (d) Reader
2. Find the missing number in the series: 9, 27, 81, 243, ?
   (a) 729 (b) 720 (c) 735 (d) 715
3. Which one does not belong with the others: Lion, Tiger, Leopard, Sparrow?
   (a) Sparrow (b) Lion (c) Tiger (d) Leopard
4. In a code, LEMON is coded as MFNPO (each letter shifted one place forward). How is SILVER coded using the same rule?
   (a) TJMWFS (b) TJMWFR (c) SJMWFS (d) TJMXFS
5. A man walks 10 km east, then 24 km north. How far is he from his starting point?
   (a) 26 km (b) 30 km (c) 34 km (d) 22 km
6. K is L's mother. M is L's son. How is K related to M?
   (a) Grandmother (b) Mother (c) Aunt (d) Sister
7. In the letter series J, M, Q, V, ?, what is the next letter (gaps +3, +4, +5, next +6)?
   (a) AB (b) AA (c) Z (d) Y
8. Given: S ≥ T > U ≥ V. Which of the following must be true?
   (a) S ≥ V (b) V > S (c) T < V (d) U > S
9. In a class of 78 students, Anjali ranks 33rd from the top. What is her rank from the bottom?
   (a) 46th (b) 45th (c) 47th (d) 44th
10. If '@' denotes '+', '#' denotes '−', '%' denotes '×', and '$' denotes '÷', evaluate: 108 $ 9 % 4 @ 30 # 20.
    (a) 58 (b) 56 (c) 60 (d) 54
11. Fourteen people sit in a row facing north. E sits at the left end. F sits immediately to the right of E. G sits ninth to the right of F. How many people sit to the right of G?
    (a) 3 (b) 4 (c) 2 (d) 5
12. Statements: All detectives are investigators. Some investigators are analysts. Conclusion: Some detectives are analysts. Does this conclusion necessarily follow?
    (a) No, it does not necessarily follow (b) Yes, it follows validly (c) Only if all investigators are detectives (d) Cannot be determined
13. In a code, MARKET is coded by each letter's position in the alphabet as 13-1-18-11-5-20. How is BUDGET coded using the same rule?
    (a) 2-21-4-7-5-20 (b) 2-21-4-7-5-19 (c) 1-21-4-7-5-20 (d) 2-20-4-7-5-20
14. Find the missing number in the series: 800, 720, 648, 583.2, ?
    (a) 524.88 (b) 520 (c) 530 (d) 515
15. A man is facing east. He turns 180°, then 90° clockwise, then 90° clockwise. Which direction is he facing now?
    (a) East (b) West (c) North (d) South
16. A is three times as old as B. Four years ago, A was four times as old as B. Find B's present age.
    (a) 12 years (b) 10 years (c) 14 years (d) 8 years
17. Find the missing number in the series: 17, 36, 74, 150, ?
    (a) 302 (b) 298 (c) 306 (d) 294
18. Which of the following is not a multiple of 13: 117, 130, 138, 143?
    (a) 138 (b) 117 (c) 130 (d) 143
19. Twelve colleagues sit in a row facing north. H sits at the right end. I sits immediately to the left of H. J sits eighth to the left of I. How many colleagues sit to the left of J?
    (a) 2 (b) 3 (c) 1 (d) 4
20. Statements: All watchtowers offer elevated views. Everything with an elevated view aids surveillance. Conclusion: All watchtowers aid surveillance. Does this follow?
    (a) Yes, it follows validly (b) No (c) Cannot be determined (d) Only partially
21. Find the missing number in the series: 7, 17, 37, 77, ?
    (a) 157 (b) 154 (c) 160 (d) 150
22. In the analogy "Carpenter is to Furniture as Weaver is to ___," the missing word is:
    (a) Cloth (b) Loom (c) Thread (d) Cotton
23. In a code, WINTER is coded as XJOUFS (each letter shifted one place forward). How is CASTLE coded using the same rule?
    (a) DBTUMF (b) DBTUMG (c) CBTUMF (d) DBTVMF
24. In a row of 100 people, Rahul is 45th from the left. What is his position from the right?
    (a) 56th (b) 55th (c) 57th (d) 54th
25. Statements: All searchlights are illumination devices. No illumination device functions without power. Conclusion: No searchlight functions without power. Does this follow?
    (a) Yes, it follows validly (b) No (c) Cannot be determined (d) Only partially

Section B: General Knowledge & Current Affairs (Q26–75)

26. Who was the first Indian to become a Field Marshal?
    (a) Sam Manekshaw (b) K.M. Cariappa (c) K.S. Thimayya (d) J.N. Chaudhuri
27. Which Article of the Indian Constitution provides for the Right against Exploitation?
    (a) Article 23 (b) Article 21 (c) Article 19 (d) Article 32
28. Which Indian city is known as the "Cotton City of India"?
    (a) Akola (b) Nagpur (c) Solapur (d) Ichalkaranji
29. The Non-Cooperation Movement was withdrawn in which year?
    (a) 1922 (b) 1920 (c) 1930 (d) 1942
30. Which is the largest artificial lake in Asia, located in India?
    (a) Upper Lake, Bhopal (b) Chilika Lake (c) Wular Lake (d) Dal Lake
31. Who was the Viceroy of India when the Indian National Army trials took place?
    (a) Lord Wavell (b) Lord Mountbatten (c) Lord Linlithgow (d) Lord Willingdon
32. The National Institute of Design is located in:
    (a) Ahmedabad (b) Mumbai (c) Bengaluru (d) Delhi
33. Which is the highest sporting honour given to a coach in India?
    (a) Dronacharya Award (b) Arjuna Award (c) Khel Ratna Award (d) Padma Shri
34. Who was the Constitutional Advisor to the Constituent Assembly of India?
    (a) B.N. Rau (b) B.R. Ambedkar (c) Jawaharlal Nehru (d) Rajendra Prasad
35. Which Indian state has the highest number of Rajya Sabha seats reserved for it after Uttar Pradesh?
    (a) Maharashtra (b) West Bengal (c) Bihar (d) Tamil Nadu
36. The Government of India Act, 1919, introduced a system of governance in provinces known as:
    (a) Dyarchy (b) Federation (c) Unitary rule (d) Direct rule
37. Which critically endangered fish-eating crocodilian is native to the Indian subcontinent's river systems?
    (a) Gharial (b) King Cobra (c) Indian Cobra (d) Python
38. Who was the first Chief Minister of Punjab (post-independence, undivided)?
    (a) Gopi Chand Bhargava (b) Partap Singh Kairon (c) Bhim Sen Sachar (d) Giani Zail Singh
39. Which Indian city is known as the "Cyberabad" for its IT hub?
    (a) Hyderabad (b) Bengaluru (c) Pune (d) Chennai
40. The Battle of Talikota, which led to the decline of the Vijayanagara Empire, was fought in which year?
    (a) 1565 (b) 1526 (c) 1556 (d) 1761
41. Which is the largest botanical garden in Asia, located near Kolkata?
    (a) Acharya Jagadish Chandra Bose Indian Botanic Garden (b) Lalbagh Botanical Garden (c) Rock Garden (d) Lodhi Garden
42. Who founded the Indian Association for the Cultivation of Science?
    (a) Mahendra Lal Sarkar (b) C.V. Raman (c) Jagadish Chandra Bose (d) Meghnad Saha
43. Which is one of the deepest gorges in the world, formed by the Brahmaputra (Yarlung Tsangpo) as it cuts through the Himalayas?
    (a) Yarlung Tsangpo/Dihang Gorge (b) Nathula Gorge (c) Silent Valley (d) Chambal Ravines
44. The Doctrine of Lapse was formally withdrawn following which event?
    (a) The Revolt of 1857 (b) The Partition of Bengal (c) The Jallianwala Bagh massacre (d) The Quit India Movement
45. Which Indian state celebrates the "Onam" harvest festival?
    (a) Kerala (b) Tamil Nadu (c) Karnataka (d) Andhra Pradesh
46. Who was the first Indian woman to win a medal at the Asian Games?
    (a) Kamaljeet Sandhu (b) P.T. Usha (c) Anju Bobby George (d) Saina Nehwal
47. Which channel separates the Andaman Islands from Myanmar's Coco Islands?
    (a) Coco Channel (b) Ten Degree Channel (c) Duncan Passage (d) Sombrero Channel
48. Who founded the Naujawan Bharat Sabha?
    (a) Bhagat Singh (b) Chandrashekhar Azad (c) Sukhdev (d) Rajguru
49. Which Indian city hosted the inaugural Indian Premier League (IPL) season's opening match, in 2008?
    (a) Bengaluru (b) Mumbai (c) Chennai (d) Kolkata
50. The "June 3rd Plan" of 1947 is also known as:
    (a) The Mountbatten Plan (b) The Cripps Plan (c) The Wavell Plan (d) The Cabinet Mission Plan
51. Which Indian state has one of the largest numbers of registered law colleges among Indian states?
    (a) Maharashtra (b) Uttar Pradesh (c) Tamil Nadu (d) Karnataka
52. Who wrote the "Ramcharitmanas"?
    (a) Tulsidas (b) Kabir (c) Surdas (d) Mirabai
53. Which is the largest tidal port in India?
    (a) Kandla Port (Deendayal Port) (b) Mumbai Port (c) Chennai Port (d) Visakhapatnam Port
54. India adopted the metric system of weights and measures officially in which year?
    (a) 1956 (b) 1947 (c) 1962 (d) 1971
55. Which Indian state is the largest producer of ginger?
    (a) Kerala (b) Karnataka (c) Meghalaya (d) Sikkim
56. Who was the first Indian to win an individual Olympic bronze medal in wrestling?
    (a) K.D. Jadhav (b) Sushil Kumar (c) Yogeshwar Dutt (d) Bajrang Punia
57. Which Indian city is known as the "Detroit of the East"?
    (a) Chennai (b) Pune (c) Gurugram (d) Jamshedpur
58. The "Digital India" programme was launched in which year?
    (a) 2015 (b) 2010 (c) 2019 (d) 2005
59. Which Indian state was carved out of Bihar in 2000?
    (a) Jharkhand (b) Chhattisgarh (c) Uttarakhand (d) West Bengal
60. Who was the Prime Minister of India during the Kargil War of 1999?
    (a) Atal Bihari Vajpayee (b) P.V. Narasimha Rao (c) I.K. Gujral (d) Manmohan Singh
61. Which highland region is associated with the highest elevations of the Vindhya Range and is also the source of the Narmada river?
    (a) Amarkantak (b) Kalsubai (c) Mahendragiri (d) Dhupgarh
62. The "Make in India" initiative primarily aims to:
    (a) Encourage manufacturing and investment in India (b) Promote foreign travel (c) Reform the judiciary (d) Expand agricultural subsidies
63. Which Indian classical dance form originated in Assam?
    (a) Sattriya (b) Kathak (c) Odissi (d) Manipuri
64. Who founded the Hindustan Socialist Republican Association?
    (a) Chandrashekhar Azad and Bhagat Singh (b) Lala Lajpat Rai (c) Bal Gangadhar Tilak (d) Bipin Chandra Pal
65. Which is the largest producer of oranges among Indian states?
    (a) Maharashtra (b) Madhya Pradesh (c) Punjab (d) Rajasthan
66. The "Individual Satyagraha" was launched by Gandhi with which leader taking the first pledge?
    (a) Vinoba Bhave (b) Jawaharlal Nehru (c) Sardar Patel (d) Rajendra Prasad
67. Which Indian state has one of the largest numbers of registered dental colleges among Indian states?
    (a) Karnataka (b) Maharashtra (c) Tamil Nadu (d) Uttar Pradesh
68. Who is considered the founder of the Hind Swaraj philosophy through his 1909 pamphlet?
    (a) Mahatma Gandhi (b) Jawaharlal Nehru (c) B.R. Ambedkar (d) Sardar Patel
69. Which is the largest sand dune desert region in India, part of the Thar?
    (a) Jaisalmer region (b) Kutch region (c) Barmer region (d) Bikaner region
70. The "Attlee Announcement" of February 1947 set a deadline for British withdrawal from India by which date?
    (a) June 1948 (b) August 1947 (c) January 1950 (d) December 1947
71. Which Indian state is the largest producer of black pepper?
    (a) Kerala (b) Karnataka (c) Tamil Nadu (d) Andhra Pradesh
72. "Vande Mataram," India's national song, was originally composed as part of which novel?
    (a) Anandmath (b) Gora (c) Ghare-Baire (d) Devdas
73. Which is the largest producer of apples among Indian states?
    (a) Jammu and Kashmir (b) Himachal Pradesh (c) Uttarakhand (d) Arunachal Pradesh
74. The "August Kranti" (August Revolution) refers to which movement?
    (a) The Quit India Movement of 1942 (b) The Non-Cooperation Movement of 1920 (c) The Civil Disobedience Movement of 1930 (d) The Khilafat Movement of 1919
75. Which Indian city is known as the "Sports Capital of India"?
    (a) Patiala (b) Chandigarh (c) Ludhiana (d) Jalandhar

Section C: Numerical Ability (Q76–90)

76. Simplify: 180 ÷ 15 + 14 × 3 − 28.
    (a) 26 (b) 24 (c) 28 (d) 22
77. A sum of ₹45,000 amounts to ₹58,500 in 3 years at simple interest. Find the rate of interest per annum.
    (a) 10% (b) 8% (c) 12% (d) 9%
78. The ratio of two numbers is 9:11. If their sum is 160, find the larger number.
    (a) 88 (b) 84 (c) 92 (d) 80
79. A shopkeeper buys an article for ₹1,440 and sells it for ₹1,800. Find the profit percentage.
    (a) 25% (b) 20% (c) 30% (d) 15%
80. Find the average of the first fifty-five natural numbers.
    (a) 28 (b) 27.5 (c) 28.5 (d) 27
81. A train 320 m long crosses a pole in 32 seconds. Find its speed in km/h.
    (a) 36 km/h (b) 30 km/h (c) 40 km/h (d) 45 km/h
82. If the cost price of 65 articles equals the selling price of 52 articles, find the profit percentage.
    (a) 25% (b) 20% (c) 30% (d) 15%
83. Find the value of: 60% of 150 + 10% of 500.
    (a) 140 (b) 135 (c) 145 (d) 130
84. A and B together can complete a piece of work in 8 days. A alone can do it in 12 days. In how many days can B alone complete it?
    (a) 24 days (b) 22 days (c) 26 days (d) 20 days
85. Find the compound interest on ₹80,000 at 5% per annum for 2 years, compounded annually.
    (a) ₹8,200 (b) ₹8,000 (c) ₹8,400 (d) ₹7,900
86. Solve for x: 14(x − 11) = 7x + 21.
    (a) 25 (b) 24 (c) 26 (d) 23
87. Find the area of a circle with radius 49 cm (use π = 22/7).
    (a) 7,546 sq cm (b) 7,500 sq cm (c) 7,600 sq cm (d) 7,450 sq cm
88. A boat's speed in still water is 26 km/h; stream speed is 4 km/h. Find the time to cover 150 km downstream.
    (a) 5 hours (b) 5.5 hours (c) 4.5 hours (d) 6 hours
89. Find the missing number in the series: 30, 60, 120, 240, ?
    (a) 480 (b) 470 (c) 490 (d) 460
90. A sum of ₹1,40,000 is divided between A and B such that A's share is 150% more than B's. Find B's share.
    (a) ₹40,000 (b) ₹38,000 (c) ₹42,000 (d) ₹36,000

Section D: Computer Knowledge (Q91–100)

91. Which of the following is used to project a computer's display onto a large screen?
    (a) Projector (b) Keyboard (c) Mouse (d) Scanner
92. What does "NIC" stand for in computer hardware?
    (a) Network Interface Card (b) Network Internet Card (c) National Interface Card (d) Network Information Card
93. Which of the following is used to record and edit audio and video?
    (a) Media editing software (b) MS Word (c) MS Excel (d) MS Access
94. What is the full form of "IoT"?
    (a) Internet of Things (b) Internet of Technology (c) Input Output Terminal (d) Integrated Online Tool
95. Which key combination is used to open a new document?
    (a) Ctrl+N (b) Ctrl+O (c) Ctrl+P (d) Ctrl+S
96. Which of the following is an example of a note-syncing cloud application?
    (a) Google Keep (b) MS Word (c) MS Excel (d) Adobe Reader
97. What does "DPI" stand for in relation to printers and scanners?
    (a) Dots Per Inch (b) Data Per Inch (c) Digital Print Index (d) Data Processing Index
98. Which of the following is used to protect data by making it unreadable without a key?
    (a) Encryption (b) Compression (c) Formatting (d) Defragmentation
99. What does "LED" stand for in computer display technology?
    (a) Light Emitting Diode (b) Light Enhanced Display (c) Liquid Emitting Diode (d) Liquid Enhanced Display
100. Which of the following is used to connect a printer wirelessly to a computer?
     (a) Bluetooth or Wi-Fi (b) A USB-only cable (c) A VGA cable (d) An HDMI cable

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Answer Key with Explanations

Section A:

1.(a) A nurse works in a hospital, just as a librarian works in a library.

2.(a) Each term triples: 9×3=27, 27×3=81, 81×3=243, 243×3=729.

3.(a) Lion, tiger, and leopard are large wild cats, while a sparrow is a bird, making it the odd one out.

4.(a) Each letter shifts one place forward: S+1=T, I+1=J, L+1=M, V+1=W, E+1=F, R+1=S, giving TJMWFS.

5.(a) By the Pythagorean theorem, distance = √(10²+24²) = √(100+576) = √676 = 26 km.

6.(a) K is L's mother, and M is L's son, so K is M's grandmother.

7.(a) The gaps increase by one each time: J(10)+3=M(13), M+4=Q(17), Q+5=V(22), V+6=AB(28).

8.(a) Since S≥T>U≥V, it follows directly that S≥V.

9.(a) Rank from the bottom = 78 − 33 + 1 = 46th.

10.(a) Following the order of operations: 108÷9=12, 12×4=48, 48+30=78, 78−20=58.

11.(a) E is at the left end (position 1); F is immediately right of E (position 2); G is ninth to the right of F, so G is at position 2+9=11; with fourteen people in the row, 3 people sit to the right of G.

12.(a) No, this does not necessarily follow: the "some investigators" who are analysts may or may not include the specific investigators who are detectives.

13.(a) Each letter is coded by its position in the alphabet; applying the same rule, BUDGET is coded as 2-21-4-7-5-20.

14.(a) Each term is multiplied by 0.9: 800×0.9=720, 720×0.9=648, 648×0.9=583.2, 583.2×0.9=524.88.

15.(a) A 180° turn plus two 90° clockwise turns totals 360° overall, a full turn, so facing east remains facing east.

16.(a) Let B's present age be x and A's be 3x; four years ago, 3x−4 = 4(x−4), giving 3x−4 = 4x−16, so x=12.

17.(a) Each term follows ×2+2: 17×2+2=36, 36×2+2=74, 74×2+2=150, 150×2+2=302.

18.(a) 117, 130, and 143 are multiples of 13, while 138 is not.

19.(a) H is at the right end (position 12); I is immediately left of H (position 11); J is eighth to the left of I, so J is at position 11−8=3; 2 people sit to the left of J (positions 1 and 2).

20.(a) Yes, this follows validly: all watchtowers offer elevated views, and everything with an elevated view aids surveillance, so all watchtowers aid surveillance.

21.(a) Each term follows ×2+3: 7×2+3=17, 17×2+3=37, 37×2+3=77, 77×2+3=157.

22.(a) A carpenter makes furniture, just as a weaver makes cloth.

23.(a) Each letter shifts one place forward: C+1=D, A+1=B, S+1=T, T+1=U, L+1=M, E+1=F, giving DBTUMF.

24.(a) Position from the right = 100 − 45 + 1 = 56th.

25.(a) Yes, this follows validly: all searchlights are illumination devices, and no illumination device functions without power, so no searchlight functions without power.

Section B:

26.(a) Sam Manekshaw was the first Indian to become a Field Marshal.

27.(a) Article 23 provides for the Right against Exploitation.

28.(a) Akola is known as the "Cotton City of India."

29.(a) The Non-Cooperation Movement was withdrawn in 1922, after the Chauri Chaura incident.

30.(a) The Upper Lake in Bhopal is one of the largest artificial lakes in Asia.

31.(a) Lord Wavell was the Viceroy of India when the Indian National Army trials took place.

32.(a) The National Institute of Design is located in Ahmedabad.

33.(a) The Dronacharya Award is the highest sporting honour given to a coach in India.

34.(a) B.N. Rau served as the Constitutional Advisor to the Constituent Assembly of India.

35.(a) Maharashtra has the second-highest number of Rajya Sabha seats after Uttar Pradesh.

36.(a) The Government of India Act, 1919, introduced Dyarchy in the provinces.

37.(a) The Gharial is a critically endangered fish-eating crocodilian native to the Indian subcontinent's river systems.

38.(a) Gopi Chand Bhargava was the first Chief Minister of Punjab post-independence.

39.(a) Hyderabad is known as "Cyberabad" for its IT hub.

40.(a) The Battle of Talikota was fought in 1565.

41.(a) The Acharya Jagadish Chandra Bose Indian Botanic Garden, near Kolkata, is the largest botanical garden in Asia.

42.(a) Mahendra Lal Sarkar founded the Indian Association for the Cultivation of Science.

43.(a) The Yarlung Tsangpo/Dihang Gorge is one of the deepest gorges in the world, formed by the Brahmaputra.

44.(a) The Doctrine of Lapse was formally withdrawn following the Revolt of 1857.

45.(a) Kerala celebrates the "Onam" harvest festival.

46.(a) Kamaljeet Sandhu was the first Indian woman to win a gold medal at the Asian Games.

47.(a) The Coco Channel separates the Andaman Islands from Myanmar's Coco Islands.

48.(a) Bhagat Singh founded the Naujawan Bharat Sabha.

49.(a) Bengaluru hosted the inaugural IPL season's opening match, in 2008.

50.(a) The "June 3rd Plan" of 1947 is also known as the Mountbatten Plan.

51.(a) Maharashtra has one of the largest numbers of registered law colleges among Indian states.

52.(a) Tulsidas wrote the "Ramcharitmanas."

53.(a) Kandla Port (Deendayal Port) is the largest tidal port in India.

54.(a) India officially adopted the metric system of weights and measures in 1956.

55.(a) Kerala is the largest producer of ginger among Indian states.

56.(a) K.D. Jadhav was the first Indian to win an individual Olympic medal in wrestling, a bronze at the 1952 Helsinki Olympics.

57.(a) Jamshedpur is known as the "Detroit of the East."

58.(a) The "Digital India" programme was launched in 2015.

59.(a) Jharkhand was carved out of Bihar in 2000.

60.(a) Atal Bihari Vajpayee was the Prime Minister of India during the Kargil War of 1999.

61.(a) Amarkantak is associated with the highest elevations of the Vindhya Range and is the source of the Narmada river.

62.(a) The "Make in India" initiative aims to encourage manufacturing and investment in India.

63.(a) Sattriya originated in Assam.

64.(a) Chandrashekhar Azad and Bhagat Singh founded the Hindustan Socialist Republican Association.

65.(a) Maharashtra is the largest producer of oranges among Indian states.

66.(a) Vinoba Bhave was the first to take the pledge in Gandhi's Individual Satyagraha.

67.(a) Karnataka has one of the largest numbers of registered dental colleges among Indian states.

68.(a) Mahatma Gandhi wrote the 1909 pamphlet "Hind Swaraj."

69.(a) The Jaisalmer region is part of the largest sand dune desert area of the Thar Desert.

70.(a) The Attlee Announcement of February 1947 set a deadline of June 1948 for British withdrawal from India.

71.(a) Kerala is the largest producer of black pepper among Indian states.

72.(a) "Vande Mataram" was originally composed as part of the novel "Anandmath."

73.(a) Jammu and Kashmir is the largest producer of apples among Indian states.

74.(a) The "August Kranti" (August Revolution) refers to the Quit India Movement of 1942.

75.(a) Patiala is known as the "Sports Capital of India."

Section C:

76.(a) 180÷15=12; 14×3=42; 12+42−28=26.

77.(a) Interest = 58,500−45,000 = ₹13,500 over 3 years; rate = (13,500×100)/(45,000×3) = 10%.

78.(a) The parts total 9+11=20; larger number = 160×11/20 = 88.

79.(a) Profit = 1,800−1,440 = ₹360; profit percentage = (360/1,440)×100 = 25%.

80.(a) The first fifty-five natural numbers sum to 1,540; average = 1,540/55 = 28.

81.(a) Speed = 320 m / 32 s = 10 m/s = 10×18/5 = 36 km/h.

82.(a) If CP of 65 articles equals SP of 52 articles, SP/CP per article = 65/52 = 1.25, a profit of 25%.

83.(a) 60% of 150 = 90; 10% of 500 = 50; sum = 140.

84.(a) Combined rate = 1/8; A's rate = 1/12; B's rate = 1/8−1/12 = 3/24−2/24 = 1/24, so B alone takes 24 days.

85.(a) Amount = 80,000×(1.05)² = 88,200; compound interest = ₹8,200.

86.(a) 14(x−11)=7x+21 gives 14x−154=7x+21, so 7x=175, x=25.

87.(a) Area = (22/7)×49² = 22×343 = 7,546 sq cm.

88.(a) Downstream speed = 26+4 = 30 km/h; time = 150/30 = 5 hours.

89.(a) Each term doubles: 30×2=60, 60×2=120, 120×2=240, 240×2=480.

90.(a) A's share is 2.5 times B's (150% more), so 3.5 parts = 1,40,000, giving B's share = ₹40,000.

Section D:

91.(a) A projector is used to project a computer's display onto a large screen.

92.(a) NIC stands for Network Interface Card.

93.(a) Media editing software is used to record and edit audio and video.

94.(a) IoT stands for Internet of Things.

95.(a) Ctrl+N is used to open a new document.

96.(a) Google Keep is an example of a note-syncing cloud application.

97.(a) DPI stands for Dots Per Inch.

98.(a) Encryption protects data by making it unreadable without a key.

99.(a) LED stands for Light Emitting Diode.

100.(a) Bluetooth or Wi-Fi is used to connect a printer wirelessly to a computer.