RRB NTPC CBT 1 2016: questions with answers

Karnataka is India's largest producer of raw silk, mainly mulberry silk, contributing roughly a third or more of the country's output. Ramanagara near Bengaluru hosts Asia's largest silk cocoon market.

Profit is shared in the ratio of capital × time. Mohan: 1,00,000 × 12. Sohan joined after x months: 40,000 × (12 − x). So 12,00,000 : 40,000(12 − x) = 3 : 1, which gives 40,000(12 − x) = 4,00,000, i.e. 12 − x = 10 and x = 2. Sohan joined after 2 months.

Complementary angles add up to 90°. In the ratio 4 : 5 they are 90 × 4/9 = 40° and 90 × 5/9 = 50°. The greater angle is 50°.

The letters of HEAR move forward by 3, 5, 7 and 9: H+3 = K, E+5 = J, A+7 = H, R+9 = A (wrapping round after Z). Applying the same to MILK: M+3 = P, I+5 = N, L+7 = S, K+9 = T, giving PNST.

Total of 12 observations = 12 × 15 = 180. Total of 13 observations = 13 × 16 = 208. The 13th observation = 208 − 180 = 28.

Ligaments are bands of tough fibrous connective tissue that connect one bone to another at joints, holding them together. Tendons connect muscles to bones, and cartilage cushions the ends of bones.

In each case the remainder is 2 less than the divisor (12 − 10 = 15 − 13 = 18 − 16 = 27 − 25 = 2). So the number is 2 less than a common multiple. LCM(12, 15, 18, 27) = 540, so the least number = 540 − 2 = 538.

Adding with the decimal points aligned: 6732.8 + 673.28 = 7406.08; + 67.328 = 7473.408; + 6.7328 = 7480.1408; + 0.67328 = 7480.81408.

Kerala was declared India's first 'complete digital state' in February 2016, after achieving 100% mobile density, high digital literacy, and broadband and Aadhaar-linked services across all its gram panchayats.

The official key treats the assertion as true and the reason as false. Rising greenhouse gases are expected to raise Earth's average temperature. The reason, as stated, narrows the effect of CO₂ to the polar regions alone, while extra CO₂ warms the whole planet, so the key marks it false.

Saina Nehwal is an Indian badminton player. She won bronze at the 2012 London Olympics and became world No. 1 in women's singles in 2015.

Pages printed in the 4th month: 256 + 563 + 347 + 651 + 412 + 321 = 2550. Average over 6 printers = 2550/6 = 425.

Five-month totals: P 2646, Q 2665, R 2595, S 552 + 438 + 527 + 651 + 582 = 2750, T 2731, U 2712. Printer S printed the most pages.

Printer Q in the 2nd month printed 441 pages and printer U in the 5th month 693. Ratio = 441 : 693; dividing both by 63 gives 7 : 11.

Rhythm is a basic element of music. In the same way, design is a basic element of a building. An architect is a person, and beauty and symmetry are qualities, not the thing being designed.

The Hotaki dynasty was a Pashtun dynasty founded by Mirwais Hotak in Kandahar in 1709. It ruled parts of Afghanistan (and briefly Persia) until 1738.

Rhizobium bacteria live in root nodules of leguminous plants (peas, beans) and convert atmospheric nitrogen into ammonia that the plant can use. Salmonella and E. coli are gut bacteria, and Pseudomonas is not a symbiotic nitrogen fixer.

The ladder, the wall and the ground form a right triangle. The angle at the ground is 60° and the foot is 6.5 m from the wall, so cos 60° = 6.5/length. Length = 6.5/0.5 = 13 metres.

In 3/5 : 34, the number is the sum of the squares of numerator and denominator: 3² + 5² = 9 + 25 = 34. Testing the options, 4/7 gives 4² + 7² = 16 + 49 = 65, which matches.

Article 21 says no person shall be deprived of life or personal liberty except according to procedure established by law. Courts have read it broadly to include the right to privacy, livelihood and a clean environment.

Earnings are shared in proportion to work done per day. Daily rates: Mayank 1/5, Deepak 1/10, Pawan 1/15, i.e. 6 : 3 : 2 (multiplying by 30). Deepak's share = 3/11 × 11,000 = Rs 3,000.

All birds are trees and all trees are papers, so all birds are papers; I follows. Only some papers are books, and those may not include any birds, so II does not follow.

A quadratic has real roots when its discriminant is ≥ 0. Here D = (−4)² − 4 × 1 × 4b = 16 − 16b ≥ 0, so b ≤ 1. (For two distinct real roots b < 1; b = 1 gives a repeated root.)

The Nobel Prize Museum is in Stockholm, Sweden, in the Old Town (Gamla stan). It opened in 2001 to mark 100 years of the Nobel Prize.

Coefficient of variation = (standard deviation / mean) × 100 = 4/20 × 100 = 20%.

Dilip is Arun's father and Rakesh's grandfather, so Arun is Rakesh's father. Badhri is the brother of Enjya's husband; since Arun is a son of Dilip, Enjya is Arun's wife and Badhri his brother. The six are Dilip, Arun, Badhri, Enjya, Rakesh and Chithra, of whom Dilip, Arun, Badhri and Rakesh are male: four.

Arun and Badhri are brothers (sons of Dilip), and Rakesh is Chithra's brother. That gives the three brothers in the family: Arun, Badhri and Rakesh.

Enjya (Eniya) is Arun's wife and Rakesh is Arun's son, so Rakesh is Enjya's son. She is the one mother in the family.

Lion, tiger and giraffe are wild animals, while the horse is a domesticated animal used by people for riding and work. So the horse is the odd one out.

Venus (and Mercury) have no natural satellites. Earth has one moon, Mars has two (Phobos and Deimos), and Jupiter has dozens.

A newborn has about 300 bones (some partly cartilage). Many fuse during growth, for example in the skull, spine and pelvis, so an adult has 206 bones.

The differences between terms are 2, 4, 6, 8, 10, 12, 14, 16, increasing by 2 each time. The next difference is 18, so the next term = 83 + 18 = 101.

The angles 2x, 5x and 8x add to 15x = 180°, so x = 12°. The smallest angle = 2 × 12 = 24°.

Lowering the price by Rs 15 (360 → 345) increases the loss by 4% of the cost price. So 4% of CP = 15, and CP = 15 × 100/4 = Rs 375.

Actor Anil Kapoor received the Master Dinanath Mangeshkar Award in 2015. The awards, given by the Mangeshkar family in memory of Lata Mangeshkar's father, honour contributions to music, drama and cinema.

Students knowing at least one language = 3000 + 2000 + 500 − 1500 − 300 − 200 + 50 = 3550 (inclusion–exclusion). Those who know none = 4000 − 3550 = 450.

Exactly two languages = (French & English − all three) + (French & Hindi − all three) + (English & Hindi − all three) = (1500 − 50) + (300 − 50) + (200 − 50) = 1450 + 250 + 150 = 1850.

By inclusion–exclusion: 3000 + 2000 + 500 − 1500 − 300 − 200 + 50 = 3550 students know at least one of the three languages.

The first 30 multiples of 9 are 9 × 1 to 9 × 30. Their average = 9 × (1 + 30)/2 = 9 × 15.5 = 139.5.

The centigrade scale is named after the Swedish astronomer Anders Celsius, who proposed it in 1742; it is now officially called the Celsius scale. Water freezes at 0 °C and boils at 100 °C at sea level.

Replacing the words: 8 × 12 + 16 ÷ 2 − 10. Multiplication and division first: 96 and 8. Then 96 + 8 − 10 = 94.

Jupiter appears orange-brown with white and cream bands: its dark belts and light zones are clouds of ammonia and other compounds moving at different speeds. The Great Red Spot is a giant storm in its southern hemisphere.

Lactobacillus bacteria turn milk into curd by fermenting its sugar, lactose, into lactic acid, which makes the milk protein coagulate. Lactobacillus also adds vitamin B12 to curd.

Suresh Prabhu, Railway Minister from 2014 to 2017, presented the Rail Budget for 2016–17 in February 2016. It was the last separate Rail Budget; from 2017 it was merged with the Union Budget.

SPM stands for Suspended Particulate Matter: tiny solid or liquid particles (dust, smoke, soot) suspended in the air. Fine particles such as PM2.5 and PM10 are major air pollutants harmful to the lungs.

ELMSL = SMELL, ERHA = HEAR, SATTE = TASTE, which are senses (or what the senses do), and IKNTH = THINK. Thinking is a mental process, not one of the senses, so IKNTH is the odd one out.

Compounded yearly at 10%, the interest for 1 year = Rs 1,000. Compounded half-yearly, the rate is 5% per half-year for 2 half-years: 10000 × (1.05² − 1) = 10000 × 0.1025 = Rs 1,025. The difference = Rs 25.

In 1327 Muhammad bin Tughlaq shifted his capital from Delhi to Devagiri in the Deccan, renaming it Daulatabad (in present-day Maharashtra). The move failed because of water shortages and distance, and the capital returned to Delhi.

Each pair of letters stands for the letter that lies between them: F_H = G, N_P = O, K_M = L, E_G = F, giving GOLF. Splitting RTSUHJBDJL into pairs, RT → S, SU → T, HJ → I, BD → C, JL → K, gives STICK.

Variance is the square of the standard deviation: 4.5² = 20.25.

The Millau Viaduct in southern France, a cable-stayed bridge designed by Norman Foster and opened in 2004, spans the valley of the river Tarn. One of its masts reaches about 343 m, making it the world's tallest bridge.

A freely suspended magnetic compass needle lines up with the Earth's magnetic field: its north pole points towards the Earth's geographic north (the magnetic north). Its other end points south, so the needle lies along the north–south line.

Under Article 53 the President of India is the Supreme Commander of the armed forces. Among the options, Ram Nath Kovind (President 2017–2022) is correct for this version of the question; the current President, since 2022, is Droupadi Murmu.

Letters have their alphabet values (B = 2, K = 11). A three-letter word's value is first + second − third: MAN = 13 + 1 − 14 = 0 and SIN = 19 + 9 − 14 = 14. So HOT = 8 + 15 − 20 = 3.

Let a = 0.4 and b = 0.2. Then 0.064 − 0.008 = a³ − b³ = (a − b)(a² + ab + b²), 0.16 − 0.04 = a² − b² = (a − b)(a + b), and the denominator is (a² + ab + b²)(a + b)³. Cancelling gives (a − b)²(a + b)/(a + b)³ = ((a − b)/(a + b))² = (0.2/0.6)² = 1/9.

The British company J. S. Fry & Sons of Bristol made the first solid chocolate bar in 1847, by mixing cocoa butter, sugar and cocoa powder into a paste that could be moulded.

Write the numbers over 100: 63/100, 1050/100, 210/100 and 420/100. LCM(63, 1050, 210, 420) = 6300, so the LCM of the decimals = 6300/100 = 63.

A camel's hump stores fat, not water. When food is scarce the camel breaks this fat down for energy (producing some water as a by-product), which helps it survive long periods in the desert.

Toes are the digits at the end of the foot; fingers are the corresponding digits of the hand.

Galileo Galilei studied pendulums and designed a pendulum-controlled clock around 1641, though he died before it was built. The first working pendulum clock was made by the Dutch scientist Christiaan Huygens in 1656, who is not among the options; that is probably why the question was dropped.

SI = P × R × T/100, so y = P × y × y/100. Solving gives P = 100/y.

Everest is the highest peak in the world. In the same way, Jupiter is the largest planet in the Solar System. The Yamuna is not the largest river, Chilika is a large lake but not the largest, and the sparrow is just one bird.

Interchanging − and ÷ turns the left side into 75 − 5 × 15 ÷ 3 + 10. Then 5 × 15 = 75 and 75 ÷ 3 = 25, so the value is 75 − 25 + 10 = 60, which matches the right side.

4 leaves remainder 1 when divided by 3, so every power of 4 also leaves remainder 1: 4¹³ ≡ 1¹³ = 1 (mod 3).

From TABLE = 84973: T 8, A 4, B 9, L 7, E 3. From CHAIR = 51462: C 5, H 1, A 4, I 6, R 2. TEACHER = T 8, E 3, A 4, C 5, H 1, E 3, R 2 = 8345132.

Taking twice as long upstream means the upstream speed is half the downstream speed: 9 + s = 2(9 − s). So 9 + s = 18 − 2s, giving 3s = 9 and s = 3 km/h (check: downstream 12 km/h, upstream 6 km/h).

Take the earning as 100. After a 60% decrease it is 40; a 60% increase on 40 adds 24, making 64. The net loss is 100 − 64 = 36%.

90 km/h = 90 × 5/18 = 25 m/s. In 20 seconds the bus covers 25 × 20 = 500 m.

Selling at Rs 408 for a 20% gain means the mixture costs 408/1.2 = Rs 340 per kg. By alligation, Assam : Darjeeling = (400 − 340) : (340 − 300) = 60 : 40 = 3 : 2.

When two lines intersect, adjacent angles lie on a straight line, so they add to 180° (supplementary); statement 1 is correct. Vertically opposite angles are equal, not supplementary (unless both are 90°), so statement 2 is incorrect.

Java was the original official language for Android app development, using the Android SDK. Since 2019 Google has preferred Kotlin, but Java remains fully supported. COBOL, FORTRAN and Ada are not used for Android.

Rajasthan is India's largest state by area (about 3.42 lakh sq km, roughly 10.4% of the country). Madhya Pradesh is second and Maharashtra third.

Unscrambled, the words are CEKRTCI = CRICKET, OHKCYE = HOCKEY, ESCSH = CHESS and OTOLABLF = FOOTBALL. Cricket, hockey and football are outdoor field games played with a ball; chess is an indoor board game, so ESCSH is the odd one out.

Inhaled air has about 21% oxygen. The body absorbs only part of it, so exhaled air still contains about 16% oxygen, along with about 4% carbon dioxide; this is why mouth-to-mouth resuscitation works.

Douglas Engelbart invented the computer mouse in the 1960s at the Stanford Research Institute. The first one was a wooden shell with two metal wheels, shown in his famous 1968 'Mother of All Demos'.

The CPU (Central Processing Unit) is called the brain of the computer because it carries out instructions, does calculations and controls the other components.

When this exam was held in 2016, Dr. Syed Nasim Ahmad Zaidi was the Chief Election Commissioner of India (April 2015 – July 2017). Navin Chawla and N. Gopalaswami were earlier CECs, and A. K. Joti succeeded Zaidi.

Decode option B: 2 ↓ 5 → 6 ← 2 ^ 6 means 2 × 5 − 6 + 2 = 6. The left side is 10 − 6 + 2 = 6, which equals the right side, so B is correct. The other options do not balance.

A monopsony is a market with only one buyer and many sellers, for example a single large employer in a town buying labour. A monopoly has one seller, a duopoly two sellers, and an oligopoly a few sellers.

Take A's efficiency as 1, so B = 3 and C = 0.75. Days taken are inversely proportional to efficiency: 1 : 1/3 : 4/3. Multiplying by 3 gives 3 : 1 : 4.

The Wildlife Institute of India divides the country into 10 bio-geographic zones: Trans-Himalaya, Himalaya, Desert, Semi-Arid, Western Ghats, Deccan Peninsula, Gangetic Plain, North-East, Coasts, and Islands.

Tamil Nadu has India's largest lignite reserves, about 80% of the total, mostly in the Neyveli area, where NLC India mines it for power generation. Rajasthan and Gujarat also have significant deposits.

Rani Lakshmibai of Jhansi died fighting the British on 18 June 1858 at Kotah-ki-Serai near Gwalior, during the Revolt of 1857.

The queen is the most powerful chess piece: it can move any number of squares horizontally, vertically or diagonally. The king is the most important piece, since the game is lost if it is checkmated, but it moves only one square at a time.

The Constitution came into force on 26 January 1950, and that day is celebrated as Republic Day, so both statements are true. Saying it is celebrated as Republic Day does not explain why the Constitution came into force then (the date was chosen to honour the 1930 Purna Swaraj declaration), so R is not the explanation of A.

From the examples: 20 − 10 = 200 means − is ×; 8 ÷ 4 = 12 means ÷ is +; 6 × 2 = 4 means × is −; 10 + 2 = 5 means + is ÷. So 100 − 10 × 1000 ÷ 1000 + 100 × 10 becomes 100 × 10 − 1000 + 1000 ÷ 100 − 10 = 1000 − 1000 + 10 − 10 = 0.

Kwality Ltd., a dairy company, had its milk processing plants in Haryana (for example at Sonipat and Palwal) and in nearby northern states. The official key marks Haryana.

Fa-Hien (Faxian) visited India between about 399 and 411 AD, during the reign of the Gupta king Chandragupta II, and described the empire's prosperity. Hiuen Tsang came later, during Harshavardhana's reign in the 7th century.

Aaravya is 50% more efficient, so he takes 18/1.5 = 12 days. Atul takes 18 − 12 = 6 days more.

Divide by 2: 3x² + 2x − 1 = 0. Factorise: (3x − 1)(x + 1) = 0, so x = 1/3 or x = −1.

'Deuce' is a tennis (lawn tennis) term for a score of 40–40 in a game. A player must then win two points in a row ('advantage' and then 'game') to win the game.

Let the height be h. At 60° the shadow is h/√3; at 30° it is h√3. The increase is h√3 − h/√3 = 2h/√3 = 30, so h = 15√3 m.

Nitrous oxide (N₂O) is called laughing gas because inhaling it causes euphoria and laughter. It is used as a mild anaesthetic in surgery and dentistry.

He charges the cost price for 100 units but gives only 80. So he receives the price of 100 units for goods that cost him 80: profit = 20 on 80 = 20/80 × 100 = 25%.

In 2016 Flipkart's CEO was co-founder Binny Bansal, who took over from Sachin Bansal in January 2016. Kalyan Krishnamurthy became CEO in January 2017.

By Kepler's first law, planets move round the Sun in elliptical orbits, i.e. ovals, or 'stretched-out circles', with the Sun at one focus. The official key marks 'stretched-out circles', which describes the same elliptical shape in everyday words.

A number is divisible by 3 if its digit sum is. 2 + 6 + 7 + Y + 2 = 17 + Y; the smallest Y that makes this a multiple of 3 is 1 (17 + 1 = 18).

After the first discount d and a second discount of 20%: 400 × (1 − d) × 0.8 = 160. So 400 × (1 − d) = 200, giving 1 − d = 0.5. The first discount = 50%.

Goecha La is a high mountain pass (about 4,940 m) in western Sikkim, in the Kangchenjunga National Park. It is popular with trekkers for its close view of Mount Kangchenjunga.

Clothes are not washed well in hard water, and hard water does contain dissolved minerals, so both statements are true. The real reason is that calcium and magnesium salts react with soap to form scum instead of lather; 'contains many minerals' is too general to explain it, so the key marks D.