Mock Test 9 — 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 "Bark is to Tree as Skin is to ___," the missing word is:
   (a) Body (b) Bone (c) Blood (d) Muscle
2. Find the missing number in the series: 4, 12, 36, 108, ?
   (a) 324 (b) 320 (c) 328 (d) 316
3. Which one does not belong with the others: Guitar, Flute, Drum, Painting?
   (a) Painting (b) Guitar (c) Flute (d) Drum
4. In a code, APPLE is coded as BQQMF (each letter shifted one place forward). How is ORANGE coded using the same rule?
   (a) PSBOHF (b) PSBOGF (c) OSBOHF (d) PSBPHF
5. A man walks 16 km north, then 30 km east. How far is he from his starting point?
   (a) 34 km (b) 38 km (c) 42 km (d) 30 km
6. E is F's mother. G is E's husband. How is G related to F?
   (a) Father (b) Uncle (c) Grandfather (d) Brother
7. In the letter series H, K, O, T, ?, what is the next letter (gaps +3, +4, +5, next +6)?
   (a) Z (b) Y (c) AA (d) X
8. Given: P > Q ≥ R > S. Which of the following must be true?
   (a) P > S (b) S > P (c) Q < S (d) R > P
9. In a class of 65 students, Ishita ranks 28th from the top. What is her rank from the bottom?
   (a) 38th (b) 37th (c) 39th (d) 36th
10. If '@' denotes '+', '#' denotes '−', '%' denotes '×', and '$' denotes '÷', evaluate: 81 $ 9 % 5 @ 20 # 13.
    (a) 52 (b) 50 (c) 54 (d) 48
11. Twelve people sit in a row facing north. Q sits at the left end. R sits immediately to the right of Q. S sits seventh to the right of R. How many people sit to the right of S?
    (a) 3 (b) 4 (c) 2 (d) 5
12. Statements: All sergeants are supervisors. Some supervisors are trainers. Conclusion: Some sergeants are trainers. Does this conclusion necessarily follow?
    (a) No, it does not necessarily follow (b) Yes, it follows validly (c) Only if all supervisors are sergeants (d) Cannot be determined
13. In a code, ARREST is coded by each letter's position in the alphabet as 1-18-18-5-19-20. How is CUSTOM coded using the same rule?
    (a) 3-21-19-20-15-13 (b) 3-21-19-20-15-12 (c) 2-21-19-20-15-13 (d) 3-20-19-20-15-13
14. Find the missing number in the series: 600, 540, 486, 437.4, ?
    (a) 393.66 (b) 390 (c) 395 (d) 400
15. A man is facing west. He turns 90° clockwise, then 90° clockwise, then 90° clockwise. Which direction is he facing now?
    (a) North (b) South (c) East (d) West
16. A is four times as old as B. Seven years hence, A will be three times as old as B. Find B's present age.
    (a) 14 years (b) 12 years (c) 16 years (d) 10 years
17. Find the missing number in the series: 14, 30, 62, 126, ?
    (a) 254 (b) 250 (c) 258 (d) 248
18. Which of the following is not a multiple of 11: 99, 110, 115, 121?
    (a) 115 (b) 99 (c) 110 (d) 121
19. Ten colleagues sit in a row facing north. T sits at the right end. U sits immediately to the left of T. V sits sixth to the left of U. How many colleagues sit to the left of V?
    (a) 2 (b) 3 (c) 1 (d) 4
20. Statements: All commissioned officers hold a rank. Everyone who holds a rank wears an insignia. Conclusion: All commissioned officers wear an insignia. 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: 5, 12, 26, 54, ?
    (a) 110 (b) 108 (c) 112 (d) 106
22. In the analogy "Musician is to Concert as Actor is to ___," the missing word is:
    (a) Play (b) Camera (c) Stage (d) Script
23. In a code, WINTER is coded as XJOUFS (each letter shifted one place forward). How is STATION coded using the same rule?
    (a) TUBUJPO (b) TUBUJPN (c) SUBUJPO (d) TUBTJPO
24. In a row of 90 people, Yash is 40th from the left. What is his position from the right?
    (a) 51st (b) 50th (c) 52nd (d) 49th
25. Statements: All armoured vehicles are protected transport. No protected transport is unarmed. Conclusion: No armoured vehicle is unarmed. 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 woman to become Chief Minister of an Indian state?
    (a) Sucheta Kripalani (b) Nandini Satpathy (c) Sheila Dikshit (d) Mayawati
27. Which Article of the Indian Constitution deals with the Right to Freedom of Religion?
    (a) Article 25 (b) Article 21 (c) Article 19 (d) Article 32
28. Which Indian city is known as the "Salt City of India"?
    (a) Kandla (b) Kutch (c) Sambhar (d) Bhavnagar
29. The Ilbert Bill controversy occurred during the tenure of which Viceroy?
    (a) Lord Ripon (b) Lord Curzon (c) Lord Lytton (d) Lord Dufferin
30. Which is the largest cold desert biosphere reserve in India?
    (a) Nanda Devi Biosphere Reserve (b) Great Himalayan National Park (c) Valley of Flowers (d) Khangchendzonga Biosphere Reserve
31. Who was the Viceroy of India during the Second Round Table Conference?
    (a) Lord Irwin (b) Lord Willingdon (c) Lord Linlithgow (d) Lord Wavell
32. The Council of Scientific and Industrial Research (CSIR) is headquartered in:
    (a) New Delhi (b) Pune (c) Bengaluru (d) Chennai
33. How many tiers does the Padma awards system have, from Padma Shri up to Padma Vibhushan?
    (a) Three (b) Two (c) Four (d) Five
34. Who was the Chairman of the Constituent Assembly's Union Powers Committee?
    (a) Jawaharlal Nehru (b) B.R. Ambedkar (c) Rajendra Prasad (d) Sardar Patel
35. Which Indian state has the highest number of Scheduled Tribes population?
    (a) Madhya Pradesh (b) Odisha (c) Maharashtra (d) Chhattisgarh
36. The Indian Councils Act of 1909 is also known as which reforms?
    (a) Morley-Minto Reforms (b) Montagu-Chelmsford Reforms (c) Mont-Ford Reforms (d) Simon Reforms
37. Which is the national fruit of India?
    (a) Mango (b) Banana (c) Guava (d) Papaya
38. Who was the first Chief Minister of Madras State (later Tamil Nadu)?
    (a) T. Prakasam (b) C. Rajagopalachari (c) K. Kamaraj (d) Omandur Ramaswamy Reddiar
39. Which Indian city is known as the "IT Capital of India"?
    (a) Bengaluru (b) Hyderabad (c) Pune (d) Chennai
40. The Battle of Wandiwash, a decisive battle between the British and French, was fought in which year?
    (a) 1760 (b) 1757 (c) 1857 (d) 1799
41. Which is the smallest National Park in India by area?
    (a) South Button Island National Park (b) Kaziranga National Park (c) Gir National Park (d) Hemis National Park
42. Who founded the All India Depressed Classes Federation?
    (a) B.R. Ambedkar (b) Jyotirao Phule (c) Periyar E.V. Ramasamy (d) Mahatma Gandhi
43. Which is the lowest-altitude point in India, a below-sea-level location?
    (a) Kuttanad, Kerala (b) Kanyakumari (c) Rann of Kutch (d) Sundarbans
44. The Regulating Act, which established a Governor-General for Bengal, was passed in which year?
    (a) 1773 (b) 1784 (c) 1793 (d) 1813
45. Which Indian state is known for the Bihu festival?
    (a) Assam (b) West Bengal (c) Odisha (d) Manipur
46. Who was the first Indian woman to win an individual Olympic medal?
    (a) Karnam Malleswari (b) P.T. Usha (c) Saina Nehwal (d) Mary Kom
47. Which channel separates Little Andaman from the Nicobar Islands?
    (a) Ten Degree Channel (b) Duncan Passage (c) Coco Channel (d) Sombrero Channel
48. Who founded the Forward Bloc party?
    (a) Subhas Chandra Bose (b) Jawaharlal Nehru (c) Bhagat Singh (d) Chandrashekhar Azad
49. Which Indian city hosted the 1982 Asian Games?
    (a) New Delhi (b) Mumbai (c) Kolkata (d) Chennai
50. The "Mountbatten Plan" of 1947 proposed:
    (a) The partition of British India into India and Pakistan (b) A unified independent India (c) Continued British rule (d) A federal union of princely states only
51. Which Indian state has one of the largest numbers of registered engineering colleges among Indian states?
    (a) Tamil Nadu (b) Maharashtra (c) Karnataka (d) Andhra Pradesh
52. Who wrote the Sanskrit text "Arthashastra"?
    (a) Kautilya (Chanakya) (b) Kalidasa (c) Banabhatta (d) Vishakhadatta
53. Which is the largest brackish water lagoon in Asia, located in India?
    (a) Chilika Lake (b) Pulicat Lake (c) Vembanad Lake (d) Ashtamudi Lake
54. The Government of India and Pakistan formally exchanged instruments of partition in which year?
    (a) 1947 (b) 1948 (c) 1950 (d) 1946
55. Which Indian state is the largest producer of soybean?
    (a) Madhya Pradesh (b) Maharashtra (c) Rajasthan (d) Karnataka
56. Who was the first Indian to win a Grand Slam tennis title?
    (a) Leander Paes (b) Sania Mirza (c) Vijay Amritraj (d) Ramanathan Krishnan
57. Which Indian city is known as the "Manchester of South India"?
    (a) Coimbatore (b) Chennai (c) Madurai (d) Salem
58. The "Operation Polo" of 1948 led to the accession of which princely state to India?
    (a) Hyderabad (b) Junagadh (c) Kashmir (d) Travancore
59. Which Indian state was formed in 2000 along with Chhattisgarh and Uttarakhand?
    (a) Jharkhand (b) Telangana (c) Goa (d) Sikkim
60. Who was the President of India when India conducted its first nuclear test, Pokhran-I, in 1974?
    (a) Fakhruddin Ali Ahmed (b) V.V. Giri (c) N. Sanjiva Reddy (d) Zakir Hussain
61. Which is the highest peak in the Aravalli Range?
    (a) Guru Shikhar (b) Mount Abu (c) Nag Pahar (d) Kumbhalgarh
62. The "Antyodaya Anna Yojana" scheme in India primarily targets:
    (a) The poorest of the poor, providing highly subsidised foodgrains (b) Higher education scholarships (c) Rural electrification (d) Urban housing
63. Which Indian classical dance form originated in Andhra Pradesh?
    (a) Kuchipudi (b) Bharatanatyam (c) Kathak (d) Odissi
64. Who founded the Indian Home Rule Society in London?
    (a) Shyamji Krishna Varma (b) V.D. Savarkar (c) Lala Hardayal (d) Madan Lal Dhingra
65. Which is the largest producer of wheat among Indian states?
    (a) Uttar Pradesh (b) Punjab (c) Madhya Pradesh (d) Haryana
66. The Indian Independence Act was passed by the British Parliament in which year?
    (a) 1947 (b) 1946 (c) 1935 (d) 1945
67. Which Indian state has the largest number of registered medical colleges among Indian states?
    (a) Karnataka (b) Tamil Nadu (c) Maharashtra (d) Uttar Pradesh
68. Who is considered the founder of the Self-Respect Movement in South India?
    (a) Periyar E.V. Ramasamy (b) C.N. Annadurai (c) M.G. Ramachandran (d) Karunanidhi
69. Which is the easternmost point of India?
    (a) Kibithu, Arunachal Pradesh (b) Indira Point (c) Kanyakumari (d) Leh
70. The "Cripps Mission" was led by which British statesman?
    (a) Stafford Cripps (b) Clement Attlee (c) Winston Churchill (d) Lord Pethick-Lawrence
71. Which Indian state is the largest producer of groundnut?
    (a) Gujarat (b) Andhra Pradesh (c) Tamil Nadu (d) Karnataka
72. Who composed the tune for India's national anthem as officially adopted?
    (a) The tune follows Rabindranath Tagore's own composition (b) A committee independent of Tagore composed it (c) Bankim Chandra Chatterjee (d) Timir Baran
73. Which is the largest producer of bananas among Indian states?
    (a) Andhra Pradesh (b) Maharashtra (c) Gujarat (d) Tamil Nadu
74. The "Quit India Resolution" was passed by the Congress at which session?
    (a) The Bombay session of August 1942 (b) The Lahore session of 1929 (c) The Karachi session of 1931 (d) The Haripura session of 1938
75. Which Indian city is known as the "City of Joy"?
    (a) Kolkata (b) Mumbai (c) Chennai (d) Bhopal

Section C: Numerical Ability (Q76–90)

76. Simplify: 156 ÷ 13 + 12 × 3 − 20.
    (a) 28 (b) 26 (c) 30 (d) 24
77. A sum of ₹36,000 amounts to ₹46,800 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 5:7. If their sum is 144, find the larger number.
    (a) 84 (b) 80 (c) 88 (d) 76
79. A shopkeeper buys an article for ₹1,200 and sells it for ₹1,500. Find the profit percentage.
    (a) 25% (b) 20% (c) 30% (d) 15%
80. Find the average of the first forty-five natural numbers.
    (a) 23 (b) 22.5 (c) 23.5 (d) 22
81. A train 280 m long crosses a pole in 28 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 55 articles equals the selling price of 44 articles, find the profit percentage.
    (a) 25% (b) 20% (c) 30% (d) 15%
83. Find the value of: 45% of 200 + 30% of 150.
    (a) 135 (b) 130 (c) 140 (d) 125
84. A and B together can complete a piece of work in 12 days. A alone can do it in 18 days. In how many days can B alone complete it?
    (a) 36 days (b) 32 days (c) 40 days (d) 30 days
85. Find the compound interest on ₹60,000 at 5% per annum for 2 years, compounded annually.
    (a) ₹6,150 (b) ₹6,000 (c) ₹6,300 (d) ₹5,900
86. Solve for x: 11(x − 9) = 5x + 15.
    (a) 19 (b) 18 (c) 20 (d) 17
87. Find the area of a circle with radius 28 cm (use π = 22/7).
    (a) 2,464 sq cm (b) 2,400 sq cm (c) 2,500 sq cm (d) 2,350 sq cm
88. A boat's speed in still water is 33 km/h; stream speed is 3 km/h. Find the time to cover 144 km downstream.
    (a) 4 hours (b) 4.5 hours (c) 3.5 hours (d) 5 hours
89. Find the missing number in the series: 18, 36, 72, 144, ?
    (a) 288 (b) 280 (c) 296 (d) 276
90. A sum of ₹1,25,000 is divided between A and B such that A's share is 300% more than B's. Find B's share.
    (a) ₹25,000 (b) ₹23,000 (c) ₹27,000 (d) ₹21,000

Section D: Computer Knowledge (Q91–100)

91. Which of the following is used to record sound input into a computer?
    (a) Microphone (b) Speaker (c) Monitor (d) Printer
92. What does "PAN" stand for in computer networking (distinct from the tax PAN)?
    (a) Personal Area Network (b) Public Area Network (c) Primary Area Network (d) Private Access Network
93. Which of the following is used for photo and image editing?
    (a) Adobe Photoshop (b) MS Word (c) MS Excel (d) MS Access
94. What is the full form of "HTTPS"?
    (a) Hypertext Transfer Protocol Secure (b) High Transfer Text Protocol Secure (c) Hypertext Transmission Protocol System (d) High Text Transfer Protocol Server
95. Which key combination is used to select all content in a document?
    (a) Ctrl+A (b) Ctrl+S (c) Ctrl+D (d) Ctrl+F
96. Which of the following is an example of an operating system for mobile devices?
    (a) Android (b) MS Word (c) MS Excel (d) Adobe Reader
97. What does "OCR" stand for?
    (a) Optical Character Recognition (b) Online Character Recognition (c) Optical Code Reader (d) Online Code Reader
98. Which of the following is used to find files and information stored across the internet?
    (a) A search engine (b) A word processor (c) A spreadsheet (d) A media player
99. What does "JPEG" stand for?
    (a) Joint Photographic Experts Group (b) Joint Picture Experts Group (c) Joint Photographic Encoding Group (d) Joint Picture Encoding Group
100. Which of the following is used to prevent unauthorised access to a computer using a physical key?
     (a) A biometric lock or security key (b) A word processor (c) A spreadsheet (d) A web browser

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Answer Key with Explanations

Section A:

1.(a) Bark covers a tree, just as skin covers the body.

2.(a) Each term triples: 4×3=12, 12×3=36, 36×3=108, 108×3=324.

3.(a) Guitar, flute, and drum are musical instruments, while painting is a visual art, making it the odd one out.

4.(a) Each letter shifts one place forward: O+1=P, R+1=S, A+1=B, N+1=O, G+1=H, E+1=F, giving PSBOHF.

5.(a) By the Pythagorean theorem, distance = √(16²+30²) = √(256+900) = √1156 = 34 km.

6.(a) E is F's mother, and G is E's husband, so G is F's father.

7.(a) The gaps increase by one each time: H(8)+3=K(11), K+4=O(15), O+5=T(20), T+6=Z(26).

8.(a) Since P>Q≥R>S, it follows directly that P>S.

9.(a) Rank from the bottom = 65 − 28 + 1 = 38th.

10.(a) Following the order of operations: 81÷9=9, 9×5=45, 45+20=65, 65−13=52.

11.(a) Q is at the left end (position 1); R is immediately right of Q (position 2); S is seventh to the right of R, so S is at position 2+7=9; with twelve people in the row, 3 people sit to the right of S.

12.(a) No, this does not necessarily follow: the "some supervisors" who are trainers may or may not include the specific supervisors who are sergeants.

13.(a) Each letter is coded by its position in the alphabet; applying the same rule, CUSTOM is coded as 3-21-19-20-15-13.

14.(a) Each term is multiplied by 0.9: 600×0.9=540, 540×0.9=486, 486×0.9=437.4, 437.4×0.9=393.66.

15.(a) Three successive 90° clockwise turns total 270°, so facing west becomes facing north.

16.(a) Let B's present age be x and A's be 4x; seven years hence, 4x+7 = 3(x+7), giving 4x+7 = 3x+21, so x=14.

17.(a) Each term follows ×2+2: 14×2+2=30, 30×2+2=62, 62×2+2=126, 126×2+2=254.

18.(a) 99, 110, and 121 are multiples of 11, while 115 is not.

19.(a) T is at the right end (position 10); U is immediately left of T (position 9); V is sixth to the left of U, so V is at position 9−6=3; 2 people sit to the left of V (positions 1 and 2).

20.(a) Yes, this follows validly: all commissioned officers hold a rank, and everyone who holds a rank wears an insignia, so all commissioned officers wear an insignia.

21.(a) Each term follows ×2+2: 5×2+2=12, 12×2+2=26, 26×2+2=54, 54×2+2=110.

22.(a) A musician performs at a concert, just as an actor performs in a play.

23.(a) Each letter shifts one place forward: S+1=T, T+1=U, A+1=B, T+1=U, I+1=J, O+1=P, N+1=O, giving TUBUJPO.

24.(a) Position from the right = 90 − 40 + 1 = 51st.

25.(a) Yes, this follows validly: all armoured vehicles are protected transport, and no protected transport is unarmed, so no armoured vehicle is unarmed.

Section B:

26.(a) Sucheta Kripalani was the first woman to become Chief Minister of an Indian state (Uttar Pradesh).

27.(a) Article 25 deals with the Right to Freedom of Religion.

28.(a) Sambhar is known as the "Salt City of India," home to India's largest inland saltwater lake.

29.(a) The Ilbert Bill controversy occurred during the tenure of Lord Ripon.

30.(a) Khangchendzonga Biosphere Reserve is a major cold-region biosphere reserve in India.

31.(a) Lord Willingdon was the Viceroy of India during the Second Round Table Conference.

32.(a) CSIR is headquartered in New Delhi.

33.(a) The Padma awards system has three tiers: Padma Shri, Padma Bhushan, and Padma Vibhushan.

34.(a) Jawaharlal Nehru chaired the Constituent Assembly's Union Powers Committee.

35.(a) Madhya Pradesh has the highest Scheduled Tribes population among Indian states.

36.(a) The Indian Councils Act of 1909 is also known as the Morley-Minto Reforms.

37.(a) The Mango is the national fruit of India.

38.(a) T. Prakasam was the first Chief Minister of Madras State.

39.(a) Bengaluru is known as the "IT Capital of India."

40.(a) The Battle of Wandiwash was fought in 1760.

41.(a) South Button Island National Park is the smallest National Park in India by area.

42.(a) B.R. Ambedkar founded the All India Depressed Classes Federation.

43.(a) Kuttanad in Kerala is a below-sea-level region, among the lowest-altitude points in India.

44.(a) The Regulating Act was passed in 1773.

45.(a) Assam is known for the Bihu festival.

46.(a) Karnam Malleswari was the first Indian woman to win an individual Olympic medal.

47.(a) The Ten Degree Channel separates Little Andaman from the Nicobar Islands.

48.(a) Subhas Chandra Bose founded the Forward Bloc party.

49.(a) New Delhi hosted the 1982 Asian Games.

50.(a) The Mountbatten Plan of 1947 proposed the partition of British India into India and Pakistan.

51.(a) Tamil Nadu has one of the largest numbers of registered engineering colleges among Indian states.

52.(a) Kautilya (Chanakya) wrote the Sanskrit text "Arthashastra."

53.(a) Chilika Lake is the largest brackish water lagoon in Asia.

54.(a) India and Pakistan formally became independent nations in 1947.

55.(a) Madhya Pradesh is the largest producer of soybean among Indian states.

56.(a) Leander Paes was the first Indian to win a Grand Slam tennis title, in doubles.

57.(a) Coimbatore is known as the "Manchester of South India."

58.(a) "Operation Polo" of 1948 led to the accession of Hyderabad to India.

59.(a) Jharkhand was formed in 2000 along with Chhattisgarh and Uttarakhand.

60.(a) Fakhruddin Ali Ahmed was the President of India when India conducted Pokhran-I in 1974.

61.(a) Guru Shikhar is the highest peak in the Aravalli Range.

62.(a) The Antyodaya Anna Yojana scheme primarily targets the poorest of the poor, providing highly subsidised foodgrains.

63.(a) Kuchipudi originated in Andhra Pradesh.

64.(a) Shyamji Krishna Varma founded the Indian Home Rule Society in London.

65.(a) Uttar Pradesh is the largest producer of wheat among Indian states.

66.(a) The Indian Independence Act was passed by the British Parliament in 1947.

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

68.(a) Periyar E.V. Ramasamy is considered the founder of the Self-Respect Movement in South India.

69.(a) Kibithu, in Arunachal Pradesh, is the easternmost point of India.

70.(a) The Cripps Mission was led by Stafford Cripps.

71.(a) Gujarat is the largest producer of groundnut among Indian states.

72.(a) The tune of India's national anthem follows Rabindranath Tagore's own composition.

73.(a) Andhra Pradesh is the largest producer of bananas among Indian states.

74.(a) The Quit India Resolution was passed at the Bombay session of the Congress in August 1942.

75.(a) Kolkata is known as the "City of Joy."

Section C:

76.(a) 156÷13=12; 12×3=36; 12+36−20=28.

77.(a) Interest = 46,800−36,000 = ₹10,800 over 3 years; rate = (10,800×100)/(36,000×3) = 10%.

78.(a) The parts total 5+7=12; larger number = 144×7/12 = 84.

79.(a) Profit = 1,500−1,200 = ₹300; profit percentage = (300/1,200)×100 = 25%.

80.(a) The first forty-five natural numbers sum to 1,035; average = 1,035/45 = 23.

81.(a) Speed = 280 m / 28 s = 10 m/s = 10×18/5 = 36 km/h.

82.(a) If CP of 55 articles equals SP of 44 articles, SP/CP per article = 55/44 = 1.25, a profit of 25%.

83.(a) 45% of 200 = 90; 30% of 150 = 45; sum = 135.

84.(a) Combined rate = 1/12; A's rate = 1/18; B's rate = 1/12−1/18 = 3/36−2/36 = 1/36, so B alone takes 36 days.

85.(a) Amount = 60,000×(1.05)² = 66,150; compound interest = ₹6,150.

86.(a) 11(x−9)=5x+15 gives 11x−99=5x+15, so 6x=114, x=19.

87.(a) Area = (22/7)×28² = 22×112 = 2,464 sq cm.

88.(a) Downstream speed = 33+3 = 36 km/h; time = 144/36 = 4 hours.

89.(a) Each term doubles: 18×2=36, 36×2=72, 72×2=144, 144×2=288.

90.(a) A's share is 4 times B's (300% more), so 5 parts = 1,25,000, giving B's share = ₹25,000.

Section D:

91.(a) A microphone is used to record sound input into a computer.

92.(a) PAN stands for Personal Area Network.

93.(a) Adobe Photoshop is used for photo and image editing.

94.(a) HTTPS stands for Hypertext Transfer Protocol Secure.

95.(a) Ctrl+A is used to select all content in a document.

96.(a) Android is an example of an operating system for mobile devices.

97.(a) OCR stands for Optical Character Recognition.

98.(a) A search engine is used to find files and information stored across the internet.

99.(a) JPEG stands for Joint Photographic Experts Group.

100.(a) A biometric lock or security key is used to prevent unauthorised access to a computer using a physical or biological identifier.