[DAY 23] 60 DAY RAPID REVISION (RaRe) SERIES for UPSC Prelims 2025 – SCIENCE & TECHNOLOGY, CURRENT AFFAIRS & CSAT TEST SERIES!

Solution (b) 

Explanation:

For a robot to be ethically correct, the robots take only permission action. All relative actions that are obligatory for robots are actually performed by them subjected to ties and conflicts among available action. All robot action cannot be explained by ordinary English. Hence option (b) is correct

Solution: (b) 

Explanation

Augmented reality (AR) is the superimposition of computer-generated images on existing environments to make them more interactive. It is utilized in the form of applications for mobile devices. Hence Statements 1 and 2 are not correct.

Virtual reality (VR) is a computer-generated simulation of real-life environments that is primarily achieved with the use of headsets. When worn, the user’s vision and hearing are stimulated to provide realistic experiences.

VR completely puts the user in a simulated reality, AR blends the virtual and real. Like VR, an AR experience involves some sort of goggles through which we can view a physical reality whose elements are augmented (or supplemented) by computer-generated sensory input such as sound, video, graphics, or GPS data. Hence Statements 3 and 4 are correct

Solution: (a)

Explanation

The Three Laws of Robotics (often shortened to The Three Laws or known as Asimov’s Laws) are a set of rules devised by science fiction author Isaac Asimov.

Asimov proposed three Laws of Robotics and later added the zeroth law

Law 0: A robot may not injure humanity or through inaction, allow humanity to come to harm

Law 1: A robot may not injure a human being or through inaction, allow a human being to come to harm unless this would violate higher-order law

Law 2: A robot must obey orders given to it by human beings, except where such orders would conflict with a higher-order law

Law 3: A robot must protect its own existence as long as such protection does not conflict with a higher-order law.

Hence Option (a) is correct.

Solution: (b)

Explanation

Robot: Different robots are made to perform different operations and for different operations, robots have different structures.

Robots with different structures are used to perform different tasks and hence have different motions.

Robots are used in industries to perform operations such as pulling, lifting, and inspections which are human motions and robots are designed to imitate them.

Hence Option (b) is correct answer.

Solution: (a)

Explanation

Bluebugging is a type of hacking technique in which an attacker gains unauthorized access to a device, such as a smartphone, by exploiting its Bluetooth connection.

Once the device is “blue bugged,” the attacker can potentially listen to calls, read and send messages, steal and modify contacts, and even install malware on the compromised device.

Hence Option (a) is correct answer.

Solution: (b) 

Explanation

Bandicoot is a robotic system for manhole and sewer line cleaning aimed at the complete elimination of manual scavenging from the face of earth.  

The Greater Hyderabad Municipal Corporation (GHMC) in 2019 procured a ‘Bandicoot’, which would help end the practice of manual scavenging. 

Hence Option (b) is the correct answer.

Solution: (c) 

Explanation:

Hanson Robotics’ most advanced human-like robot, Sophia, personifies our dreams for the future of AI.  

• As a unique combination of science, engineering, and artistry, Sophia is simultaneously a human-crafted science fiction character depicting the future of AI and robotics, and a platform for advanced robotics and AI research.  
• The character of Sophia captures the imagination of global audiences. She is the world’s first robot citizen and the first robot Innovation Ambassador for the United Nations Development Programme. 

Hence Option (c) is the correct answer.

Solution: (d)

Explanation: 

Recently, India joins global partnership on Artificial Intelligence (GPAI) as a founding member to support the responsible and human-centric development and use of AI. 

• It is an international and multi-stakeholder initiative including USA, UK, EU, Australia, Canada, France, Germany, Italy, Japan, Mexico, New Zealand, republic of Korea, Singapore. 
• It guides the responsible development and use of AI, grounded in human rights, inclusion, diversity, innovation and economic growth. 
• This is also a first initiative of its type for evolving better understanding of the challenges and opportunities around AI using the experience and diversity of participating countries. 

It will be supported by a secretariat, to be hosted by organization for economic cooperation and development (OECD) in Paris, as well as by two centres of expertise one each in Montreal and Paris. 

Hence all statements are correct.

Solution: (b)

Explanation

• The word ‘Vyommitra’ is made up of two words of the Sanskrit language ‘Vyom’ and ‘Mitra’ which means space and friend respectively. 
• This is the prototype of the half-humanoid female robot developed by ISRO. 
• It was unveiled on 22 January 2020.

Hence Option (b) is correct answer.

Solution: (a) 

Carbon fibre is a material consisting of very thin filaments of carbon atoms. Carbon Fibers are Fibers characterized by a carbon content of 90% or higher. The principal rationale behind the aerospace industry’s adoption of carbon Fiber lies in the weight reduction it offers. Hence, Statement 1 is correct

Carbon fibre is environmentally friendly and exhibits a longer life cycle. There are numerous technologies to recycle carbon fibres. Hence Statement 2 is not correct

option (d) is correct answer

Natural NPs are sourced from forest fires, volcanic eruptions, weathering, dust storms etc. E.g., iron oxides/sulphides, silver, and gold. Hence Statement 1 is incorrect

In order to provide an adequate level of sun protection, titanium dioxide and zinc oxide are frequently added to cosmetics among the metal and metal oxide nanoparticles (NPs) that may be present. Hence Statement 2 is correct

Workers including engineers, scientists, and technicians are mostly exposed at work while creating goods using nanomaterials, while on the other hand customers get exposed to such nanomaterials through usage and application, which may have hazardous and detrimental impacts. Hence Statement 3 is correct

Solution (c) is correct

Explanation

Carbon nanotubes have a high surface area, they go into the cell by the millions, and can have a very high efficiency of delivery to a specific cell. Hence Statement 1 is correct.

Carbon nanotubes cannot be made into artificial blood capillaries for an injured part of the human body as they are promising drug delivery platforms that can be functionalized with a variety of biomolecules, such as antibodies, proteins, or DNA. Hence Statement 2 is incorrect.

NASA has successfully demonstrated a miniaturized electronics technology with extremely high sensitivity and simplified sample preparation for in-vitro detecting specific biomarker signatures, which is based on incorporating embedded vertically aligned carbon nanotubes as nanoelectrode arrays in diagnostics devices. Hence Statement 3 is correct.

Multiple types of microbes, including bacteria and fungi, have the ability to degrade carbon nanotubes (CNTs). Hence Statement 4 is correct.

Solution: option (c) 

• Nanotechnology deals with the understanding and controlling of matter at level of 1 and 100 nano-meters, where unique phenomena enable novel applications. 
• Targeted drug distribution by nanoscale drug carriers is one of the fundamental tenets of nanomedicine. Numerous nanoscale drug delivery technologies, such as liposomes, dendrimers, quantum dots, nanotubes, polymeric biodegradable nanoparticles, and nano-capsules, have been studied. 
• In addition to enabling new therapeutic classes and encouraging the re-investigation of previously unfeasible new molecular entities that are pharmaceutically suboptimal but biologically active, nanoscale delivery vehicles can improve the therapeutic efficacy and minimise side effects associated with existing medications. 
• The development of medical nanotechnology can significantly advance genetic treatment. If diseases are handled from a genetic perspective, they are simple to treat. Therefore, using nanotechnology will enable medical professionals to treat illnesses by focusing on their fundamental causes rather than just their symptoms.

One of the key aspects of nanomedicine is targeted drug delivery by nanoscale drug carriers. Hence Statement 1 is correct.

Medical nanotechnology can largely contribute to genetic therapy and improvement. Hence Statement 2 is correct

Solution:(c)

Explanation

Sodium lamps emit light in all directions i.e., 360 degree. Because at least half of the light must be reflected and redirected to the intended area of illumination, this technique is significantly inefficient. LEDs, however, emit light in all 180 degrees. Since light is frequently needed over a target region, this is usually advantageous (rather than all 360 degrees around the bulb). Hence Statement 1 is correct. 

High Pressure Sodium (HPS) lights or Sodium lamps have a typical lifespan for sodium lights or sodium lamps is in the range of 24,000 hours. At the halfway point of their lifespan, HPS lamps continue to provide 90% of their initial light output, according to American Electric Lighting. Lumen maintenance at the end of its useful life is still very good at 80%. LEDs have a longer lifespan than any other commercially available light source. Hence Statement 2 is incorrect. 

Monochromatic light means that the light has a single wavelength, for e.g., sodium light. The LED light is not monochromatic because it is made up of different wavelengths, therefore is polychromatic. Hence Statement 3 is correct.

Solution (b)

Explanation:

• Nanotechnology is a technology for building or constructing materials, devices, tools etc. in smallest or lowest possible form i.e. on the scale of atom and molecule. One nanometre is a one billionth of a meter. Hence, statement a is correct. 
• Applications of this technology will help manufacturing products at reduced cost which will be smaller, lighter and cheaper. Hence, statement b is incorrect.
• The Nanotechnology is believed to be very promising in bringing solutions in the fields of health and sanitation, food security and environmental issues.

Nanotechnological inventions would bring enormous benefits and luxury in human life. It is widely believed that nanotechnology has got the much needed potential to be effective in terms of energy consumption besides being environment friendly. It is also expected to solve major health problems. Hence, statement c is correct.

Solution (d)

Explanation:

• Nanoscience and nanotechnology are the study and application of extremely small things and can be used across all the other science fields, such as chemistry, biology, physics, materials science, and engineering. Nanotechnology is science, engineering, and technology conducted at the nanoscale, which is about 1 to 100 nanometers.
• Carbon nanotubes (CNTs) have emerged as the foremost nanomaterial (NM) for water purification. It can remove almost all three types of pollutants, i.e. organic, inorganic and biological pollutants. This is because of their large surface area, high aspect ratio and greater chemical reactivity along with lower cost and energy.  Hence Statement 1 is correct.
• Using chemical reactions, nanoparticles are being developed to clean industrial water pollutants in groundwater. Researchers are also designing magnetic water repellent nanoparticles that can be used in oil spills to remove oil from the water by using magnets. Hence Statement 2 is correct.

Researchers are developing wires containing carbon nanotubes that will have much lower resistance than the high-tension wires currently used in the electric grid, thus reducing transmission power loss. Hence Statement 3 is correct.

Solution: (d)

Explanation
Nano India Mission

• The Government of India launched the Nano Mission in May 2007 as an “umbrella capacity-building program”.
• It envisages the overall development of Nanotechnology in the country and taps some of its applied potential for a nation’s development.
• The objectives of the Nano-Mission include:
• Basic Research Promotion: Funding of basic research by individual scientists and/or groups of scientists and the creation of centers of excellence for pursuing studies related to the Nanoscale.
• Infrastructure Development for Nano Science & Technology Research: It focuses on facility development for technologies like Optical Tweezers, Nano Indenter, Transmission Electron Microscope (TEM), Atomic Force Microscope (AFM), Scanning Tunneling Microscope (STM), Microarray Spotter & Scanner, etc.
• Nano Applications and Technology Development Programmes: The Mission proposes to promote application-oriented R&D Projects, establish Nano Applications and Technology Development Centers, Nano-Technology Business Incubators.
• Human Resource Development: The Mission focuses on providing effective education and training to researchers and professionals in diversified fields so that a genuine interdisciplinary culture for nanoscale science, engineering and technology can emerge.
• International Collaborations: Apart from exploratory visits of scientists, organization of joint workshops and conferences and joint research projects, it focuses to facilitate access to sophisticated research facilities abroad, establish joint centers of excellence and forge academia-industry partnerships at the international level wherever required and desirable.

   Hence correct answer is Option (d).

Solution (d)
Explanation

Naturally occurring nanoparticles can be found in volcanic ash, ocean spray, fine sand and dust, and even biological matter (e.g. viruses). Synthetic nanoparticles are equally, if not more diverse than their naturally occurring counterparts. Hence Statement 1 is incorrect

The field of nanotechnology is being greatly explored by cosmetic industries in order to improve the efficacy of cosmetic products. The cosmetics are formulated by using different types of metal and metal oxide nanoparticles such as silver nanoparticles, gold nanoparticles (AuNPs) and titanium dioxide nanoparticles (TiO2 NPs), zinc oxide nanoparticles, iron oxide nanoparticles, (Fe2O3 NPs) and carbon-based NPs. The applications of different metal oxides as one of the active ingredients in cosmetics and sunscreens have attracted enormous interest from cosmetologists with advanced knowledge of chemistry, toxicology, dermatology, rheology, and even marketing. Hence, Statement 2 is correct

According to the National Nanotechnology Initiative thousands of tons of silica, alumina and ceria, in the form of ultrafine abrasive particle mixtures including nanoparticles, are used each year in slurries for precision polishing of silicon wafers. The exposed population to nano materials continues to increase as their application expands. Despite obvious benefits of the power of small materials, there are open questions about how the nanoparticles used for day-to-day life may affect the environment. One of the crucial issues that have to be addressed in the near future, before massive fabrication of nano materials, is their toxicity to humans and impact on the environment. Hence, Statement 3 is correct

 Solution: (d)

Explanation

Nanotechnology in Food Processing

Nanotechnology offers some exciting potential benefits for the quality and safety of our foods such as:

• Contamination Sensor: Flashlight to reveal the presence of E. coli bacteria.
• Antimicrobial Packaging: Edible food films made with cinnamon or oregano oil, or nanoparticles of zinc, calcium other materials that kill bacteria.
• Improved Food Storage: Nano-enhanced barrier keeps oxygen-sensitive foods fresher.
• Enhanced Nutrient Delivery: Nano-encapsulating improves the solubility of vitamins, antioxidants, healthy omega oils and other ‘nutraceuticals’.
• Green Packaging: Nano-fibers made from lobster shells or organic corn are both antimicrobial and biodegradable.
• Pesticide Reduction: A cloth saturated with nanofibers slowly releases pesticides, eliminating the need for additional spraying and reducing chemical leakage into the water supply.
• Tracking, Tracing Brand Protection: Nanobarcodes can be created to tag individual products and trace outbreaks.
• Texture: Food spreadability and stability improve with nano-sized crystals and lipids for better low-fat foods.
• Flavour: Trick the tongue with bitter blockers or sweet and salty enhancers.
• Bacteria Identification and Elimination: Nano carbohydrate particles bind with bacteria so they can be detected and eliminated.

Hence correct answer is Option (d).

Solution: (b)

Explanation

Nanotechnology

• The idea of nanotechnology was born in 1959 when physicist Richard Feynman gave a lecture exploring the idea of building things at the atomic and molecular scale.
• The term ‘Nanotechnology’ was coined in 1974 by Norio Taniguchi of Tokyo Science University to describe semiconductor processes such as thin-film deposition that deal with control on the order of nanometers.
• Nanotechnology is science, engineering, and technology conducted at the nanoscale, which is about 1 to 100 nanometers.
• Nanoscience and nanotechnology are the study and application of extremely small things and can be used across all the other science fields, such as chemistry, biology, physics, materials science, and engineering.
• An Atomic force microscope is a scientific instrument that can generate images of nanoscale details on a physical surface by scanning small nanoscale probes.

Hence correct answer is Option (b).

Solution (b)

Statement Analysis:

Context: To contain the diphtheria outbreak in the Deeg district after seven deaths were reported within a month and 24 samples tested positive, teams of the state health department and World Health Organization (WHO) have landed in the district and started vaccination.

• Diphtheria is a contagious bacterial infection of the nose and throat. Hence statement 1 is incorrect.
• It is caused by strains of bacteria called Corynebacterium diphtheriae that make a toxin.
• When the bacteria get into and attach to the lining of the respiratory system, they can cause weakness, sore throat, mild fever, and swollen glands in the neck.
• The bacteria make a toxin that kills healthy tissues in the respiratory system. Within two to three days, the dead tissue forms a thick, grey coating that can build up in the throat or nose. 
• It can spread from person to person through respiratory droplets. Hence statement 2 is correct.
• People can also get sick from touching infected open sores or ulcers.
• It can infect the skin, causing open sores or ulcers. However, diphtheria skin infections rarely result in severe disease.
• Symptoms include sore throat, fever, chills, swollen lymph nodes, skin sores, and weakness.
• It affects children from newborns to 16 years of age. Hence statement 3 is correct.
• Treatments include antibiotics, vaccine, and an antitoxin that neutralizes the diphtheria toxin. 

Solution (d)

Statement Analysis:

Context: India launched a revamped e-Migrate portal and mobile app to facilitate Indians to travel overseas legally with safety.

• e-Migrate Portal promotes safe and legal mobility channels for Indian migrants. Hence statement 1 is correct.
• It is an online platform launched by the Government of India to facilitate and manage the migration of Indian workers seeking employment abroad.
• It aligns with the United Nations’ Sustainable Development Goal 10, promoting orderly and responsible migration.
• It offers 24/7 multilingual helpline support to Indian workers abroad. Hence statement 2 is correct.
• It aims to provide a safe and transparent framework for migrant workers by offering various services, including information access, documentation, helpline support, integration with services, and awareness campaigns
• It integrates with Digilocker, enabling secure, paperless document submission. Hence statement 3 is correct.
• It supports job-seekers by offering a one-stop marketplace for overseas employment opportunities.

Solution (d)

Statement Analysis:

Context: The latest example of the use of the ossification test came when one of those accused of killing Baba Siddique told a court in Mumbai that he should be tried as a juvenile, claiming he was 17 years old.

An Ossification Test is a medical procedure that analyses bones to determine age. This test involves taking X-rays of certain bones in the body, such as the clavicle, sternum, and pelvis, to determine the degree of growth in our bones. It is commonly used in forensic science and legal contexts to accurately determine an individual’s age when needed. Hence option d is correct.

Note:

• Ebola virus disease is a severe, often fatal illness in humans caused by the Ebola virus. It is transmitted to people from wild animals and spreads through human-to-human transmission.
• Cryptosporidiosis is a parasitic disease caused by the protozoan Cryptosporidium, which can be transmitted to humans through contaminated water, food, or contact with infected animals.

Solution (b)

Statement Analysis:

Context: There have been reports of landslides in the Kedarnath hills, the sinking of the Varunavat mountain, the melting of snow from Om Parvat, and the latest to the litany of bad news is the shrinking of the glacial lake Roop Kund. 

    Hence option b is correct.

Solution (c)

Statement Analysis:

Context: Seventy-nine years after Hiroshima and Nagasaki were subject to unprecedented devastation following the U.S.’s act of dropping atomic bombs on these cities, Nihon Hidankyo, the organization that worked for the welfare of the survivors — called the hibakusha — and steadfastly sought to build consensus on the need for the abolition of nuclear weapons, has been awarded the Nobel Peace Prize for 2024.

• Hibakusha is the Japanese word for survivors of the 1945 atomic bomb attacks on Hiroshima and Nagasaki. Hence option c is correct.
• On August 6, 1945, the United States dropped the Little Boy atomic bomb on Hiroshima, Japan. Three days later, the US dropped a second atomic bomb, known as Fat Man, on Nagasaki, Japan. By the end of 1945, more than 200,000 people died as a direct result of these bombings. 
• Currently, the combined number of ‘hibakusha’ who are alive is officially 1,06,825, according to Japan’s Ministry of Health, Labour and Welfare.

Solution (a)

Statement Analysis:

Context: India recently concluded a deal with the US for the procurement of 170 AGM-114R Hellfire missiles.

• Hellfire Missile is a short-range air-to-ground tactical missile. Hence statement 1 is incorrect.
• It is a laser-guided and subsonic tactical missile.
• It is used by the United States military as well as 30 of its allies. Hence statement 2 is incorrect.
• It has a length of 1.62 m, a diameter of 17.7 cm, and a wingspan of 0.71 m.
• Each Hellfire weighs 45.4 kg-49 kg including an 8 kg-9 kg multipurpose warhead.
• It is propelled by a single-stage solid-propellant solid-fuel rocket motor and has a maximum velocity of 950 mph.

It is used to target armoured vehicles. It includes tanks, bunkers, radar systems and antennas, communications equipment, soft targets, or hovering helicopters. Hence statement 3 is correct.

Solution (b)

Statement Analysis:

Context: The month-long strike at Samsung’s manufacturing facility in Tamil Nadu has brought to the spotlight the stressful working conditions in these factories shaped and determined by their management philosophy, which draws inspiration from the Japanese production method called Kaizen.

The “Kaizen method” is well-known as the business philosophy that encourages continuous improvement involving employees at all levels of a company. Hence option b is correct.

The concept of kaizen encompasses a wide range of ideas. Those include making the work environment more efficient by creating a team atmosphere, improving processes and procedures, ensuring employee engagement, and making jobs more fulfilling, less tiring, and safer. The goal of Kaizen is to make small changes over a period of time to drive continuous improvement within a company.

Note: 

• Jidoka is a business philosophy that emphasizes building quality into processes by empowering workers to stop production and address problems.
• Hoshin Kanri is a business philosophy that encourages continuous improvement by ensuring that everyone in the organization is aware of and working towards the same objectives.
• Shuhari is a business philosophy that emphasizes continuous growth and improvement through progression from following rules to breaking them and finally transcending them.

Solution (c)

Statement Analysis:

Context: In the heart of India’s legal system, from the Supreme Court in Delhi to modest district courts in rural Bihar, a quiet revolution has been in the making for decades. This revolution is not about abrogating colonial laws, drafting new laws, or ensuring speedier verdicts. Instead, it centres on the question — who foots the bill for justice? In this context, the idea of Third-Party Litigation Funding (TPLF) has quickly emerged as a game-changer, potentially opening courtroom doors for many who felt they had been shut out.

• Third-Party Litigation Funding (TPLF) often referred to as litigation finance, is a financial arrangement in which a third party (with no prior connection to the litigation) in a legal dispute provides funding to support the plaintiff’s pursuit of a legal claim. Hence statement 1 is correct.
• In return, the third-party funder receives a portion of the proceeds if the case is successful.
• Plaintiffs do not have to repay the funding if their lawsuit is not successful.
• This funding model allows entities to bring lawsuits without shouldering the financial risks associated with litigation.
• The emergence of TPLF has been driven by various factors, including the escalating costs of legal proceedings, the complexity of modern litigation, and the desire to level the playing field between parties with disparate financial resources.
• Disputes that attract TPLF generally include commercial contracts, international commercial arbitration, class action suits, tortious claims like medical malpractice and personal injury claims, anti-trust proceedings, insolvency proceedings, and other like claims that have a calculated chance of resulting in a substantial monetary award. Hence statement 2 is correct.
• TPF is not expressly prohibited in India.  Several judgments highlight its benefits and express that there is a need for its regulation. 

Solution (b)

Statement Analysis:

Context: The Drugs Technical Advisory Board (DTAB), the highest statutory decision-making body on technical matters related to drugs in the country, has recommended the inclusion of all antibiotics in the definition of new drugs in the New Drugs and Clinical Trial (NDCT) Rules of 2019.

• The Drugs Technical Advisory Board (DTAB) is the highest statutory decision-making body on technical matters related to drugs in India. Hence statement 1 is incorrect.
• It is established as per the Drugs and Cosmetics Act of 1940. Hence statement 2 is correct.
• It advises both the central government and state governments on technical matters arising out of the administration of the Drugs and Cosmetics Act of 1940. Hence statement 3 is incorrect.

It works under the Ministry of Health and Family Welfare. Hence statement 4 is correct.

Solution (d)

Statement Analysis:

Context: In its latest World Energy Outlook, the International Energy Agency said India will see the largest energy demand growth of any country or region in the world over the next three decades.

Reports released by the International Energy Agency (IEA):

• Energy Technology Perspectives 
• World Energy Investment 
• Global EV Outlook 
• World Energy Outlook
• Oil Market Report 
• Net Zero Roadmap
• Electricity Market Report 

Hence option d is correct.

Solution (d) 

Statement analysis:

Option (a) is incorrect: Though true, this is not the main inference of the passage. The passage reflects how economic capital and natural and human capital are important for growth, and so all of them should be taken in account to measure and achieve sustainable development.  

Option (b) is incorrect: The passage does not include the context of the role of government per se. It only mentions that GDP has certain limitations, but that does not mean giving up GDP completely as suggested in the option. So, this option is not the logical inference from the passage. 

Option (c) is incorrect: Though true, this statement covers only a part of the argument presented in the passage.  

Option (d) is correct: The following lines in the passage – “It is a multipurpose indicator capable of measuring not only traditional stocks of wealth but also those less tangible and unseen—such as educational levels, skill sets, health care, as well as environmental assets and the functioning of key ecosystem services that form the backbone of human well-being and ultimately set the parameters for sustainable development”, show that economic capital, human capital and natural capital determine sustainable growth/development. So, it is correct to infer that economic, human and natural capital should be the parameters of growth. 

Solution (d) 

Explanation:

Volume of the cube = a3 Where, a = side of the cube. 

So, a3 =  43 a = 4 cm. 

So, side of the original cube = 4 cm. 

When the four cubes are joined end to end, the length of the resulting figure (a cuboid) will be the sum of the lengths of all the four cubes, however the width and height will be the same as the original cube. 

So, the total surface area = 2(lb + bh + hl), 

Where l = length = 4+4+4+4 = 16 cm; b = breadth = 4 cm and h = height = 4 cm. 

Hence, the total surface area = 2(164 + 44 + 416) = 2144 = 288 cm2. Hence, option (d) is the correct answer.

Solution (d) 

Explanation:

As per the question, Anjali (70%) > Anika > Alka Now, Anamika scored fewer marks than only Anshika. 

So, Anshika > Anamika > Anjali (70%) > Anika > Alka 

The one who scored the minimum marks secured 65%, and the one who scored the highest achieved 87%.  Anshika (87%) > Anamika > Anjali (70%) > Anika > Alka (65%) Hence, option (d) is correct.  

Solution (b)

Explanation:

We know that there would be 12 vertices in a polygon having 12 sides. And, to form a triangle we need just 3 vertices of the polygon.

Then, required number of triangles would be equal to the number of ways in which 3 vertices can be chosen out of 12 vertices.

∴ Required number of ways- = 12C3

= (12!)/{3! × 9!} = 220 ways

Hence, the required number of triangles is 220.

Solution (b)

Explanation:

Given: 

The cuboid is a cube itself, and the ratio of a pair of sides of cuboid is 1 : 2.

No two edges of the cuboid are of equal length. A cuboid can never be divided into two identical cubes.

Concept to be used:

Dimensions of a cuboid and cube – a cuboid has three dimensions (length, width, height) while a cube has all three dimensions equal. If a cuboid is divided into two equal parts, each being a cube, then effectively one dimension of the cuboid must be twice the dimension of the cubes, while the remaining two dimensions are equal to the cube’s dimension.

Calculation:

Statement 1 is False. A cuboid does not have to be a cube itself. It can have distinct length, breadth, and height.

Statement 2 is True. One side of the cuboid (the one that’s divided) is twice the length of a side of the cube, while the other two sides are the same length as the sides of the cube.

Statement 3 is False. Two sides should be of the same length as the sides of the cube.

Statement 4 is False. If one of the dimensions of the cuboid is exactly twice the other two (which are equal), then the cuboid can be divided into two identical cubes.

∴ Only Statement 2 – “The ratio of a pair of sides of cuboid is 1 : 2” – is definitely true when a cuboid is divided into two equal parts, each part being a cube.