DAY – 12(InstaTest-12): Insta 70 Days Revision Plan-2021: Topic – SCIENCE & TECHNOLOGY, Subject-wise Test 27 , Textbook-wise Tests 7, 8, 9 Revision , August 2020 CA

Solution: B

Dengue is not eradicated from India.

https://www.healthissuesindia.com/infectious-diseases/

Solution: D

NTDs are found in several countries in Africa, Asia, and Latin America. NTDs are especially common in tropical areas where people do not have access to clean water or safe ways to dispose of human waste.

Polio is not a neglected tropical disease.

https://www.cdc.gov/globalhealth/ntd/diseases/index.html

Solution: C

Both the statements are correct.

Scientists have developed light-activated nanoparticles — each roughly 20,000 times smaller than the thickness of a single human hair and have shown in lab tests that these “quantum dots” are more than 90% effective at wiping out antibiotic-resistant germs like Salmonella, E. coli and Staphylococcus.

What are Quantum dots?

A quantum dot is a nanoparticle made of any semiconductor material such as silicon, cadmium selenide, cadmium sulfide, or indium arsenide. They are essentially small crystals of nanometer-size dimensions – they’re about 20,000 times smaller than the width of a human hair. They are each one million times smaller than a millimeter. They have distinctive electrical conduction properties that are determined by the incredibly small size and structure.

• When these QDs are hit with a specific frequency of radiation, their changeable structure, tailored by scientists, means that they can be finely tuned to emit a specific frequency of radiation; changing the wavelength of the light source can achieve the same effect.
• In the dark, the QDs remain inactive. When bombarded by visible light, they become energetically “excited.”

Why we need them?

Super-bacteria resistant to the latest antibiotics, the last line of medical defence against various infections, cancer and HIV, is on the rise. These superbugs use evolutionary abilities to overwhelm medical advances. And to contain these bugs has been a challenging task for the scientists across the world.

What led to their rise?

The rampant, indiscriminate administration of common antibiotics has allowed these bacteria the ability to shuffle their genes and defeat these drugs. Such bacteria include Salmonella, Staphylococcus and E. coli.

Solution: D

LiFi (Light Fidelity) is a wireless optical networking technology that uses light-emitting diodes (LEDs) for data transmission.

LiFi is designed to use LED light bulbs similar to those currently in use in many energy-conscious homes and offices. However, LiFi bulbs are outfitted with a chip that modulates the light imperceptibly for optical data transmission. LiFi data is transmitted by the LED bulbs and received by photoreceptors.

Benefits of LiFi

1. Higher speeds than Wi-Fi.
2. 10000 times the frequency spectrum of radio.
3. More secure because data cannot be intercepted without a clear line of sight. LiFiuses light sources to transmit data. WiFi uses radio waves to transmit data. Radio waves can pass through pretty much all objects, which makes it susceptible to piggybacking and potentially the theft of data. Light waves can’t pass through walls and other objects, which makes it more secure than WiFi.
4. Prevents piggybacking.
5. Eliminates neighboring network interference.
6. Unimpeded by radio interference.
7. Does not create interference in sensitive electronics, making it better for use in environments like hospitals and aircraft.

Solution: C

Both the statements are correct.

What are Blockchains?

Blockchains are a new data structure that is secure, cryptography-based, and distributed across a network.

1. The technology supports cryptocurrencies such as Bitcoin, and the transfer of any data or digital asset.
2. Spearheaded by Bitcoin, blockchains achieve consensus among distributed nodes, allowing the transfer of digital goods without the need for centralized authorisation of transactions.

How it operates?

1. The technology allows transactions to be simultaneously anonymous and secure, peer-to-peer, instant and frictionless.
2. It does this by distributing trust from powerful intermediaries to a large global network, which through mass collaboration, clever code and cryptography, enables a tamper-proof public ledger of every transaction that’s ever happened on the network.
3. A block is the “current” part of a blockchain which records some or all of the recent transactions, and once completed, goes into the blockchain as permanent database.
4. Each time a block gets completed, a new block is generated. Blocks are linked to each other (like a chain) in proper linear, chronological order with every block containing a hash of the previous block.

Solution: D

The Understanding Nanotechnology Website is dedicated to providing clear and concise explanations of nanotechnology applications. Scan the listings below to find an application of interest, or use the navigation bar above to go directly to the page discussing an application of interest.

https://www.understandingnano.com/nanotech-applications.html

Solution: D

Coronaviruses (CoV) are a large family of viruses that cause illness ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS-CoV).

Coronavirus disease (COVID-19) is a new strain that was discovered in 2019 and has not been previously identified in humans.

Coronaviruses are zoonotic, meaning they are transmitted between animals and people.  Detailed investigations found that SARS-CoV was transmitted from civet cats to humans and MERS-CoV from dromedary camels to humans. Several known coronaviruses are circulating in animals that have not yet infected humans.

Common signs of infection include respiratory symptoms, fever, cough, shortness of breath and breathing difficulties. In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death.

https://www.who.int/health-topics/coronavirus

Solution: A

Swine flu is an infection caused by a virus. It’s named for a virus that pigs can get. People do not normally get swine flu, but human infections can and do happen.

Swine Flu is a highly contagious acute respiratory disease of pigs caused by type A influenza virus. In 2009 a strain of swine flu called H1N1 infected many people around the world.

The virus is contagious and can spread from human to human. Symptoms of swine flu in people are similar to the symptoms of regular human flu and include fever, cough, sore throat, body aches, headache, chills and fatigue.

Swine flu viruses do not normally infect humans. However, sporadic human infections with swine flu have occurred. Children younger than five years old and adults who are 65 years and above, patients with chronic pulmonary condition (including asthma), , neurological, neuromuscular or metabolic disorders (including diabetes), obese adults and pregnant women are in the high risk group

There are antiviral medicines you can take to prevent or treat swine flu. There is a vaccine available to protect against swine flu

https://www.thehindu.com/sci-tech/health/states-put-on-high-alert-as-swine-flu-cases-spike-across-the-country/article26063610.ece

Solution: A

Viral hepatitis is an infection that causes liver inflammation and damage.

Inflammation is swelling that occurs when tissues of the body become injured or infected. Inflammation can damage organs. Researchers have discovered several different viruses NIH external link that cause hepatitis, including hepatitis A, B, C, D, and E.

Hepatitis A and hepatitis E typically spread through contact with food or water that has been contaminated by an infected person’s stool. People may also get hepatitis E by eating undercooked pork, deer, or shellfish.

Hepatitis B, hepatitis C, and hepatitis D spread through contact with an infected person’s blood. Hepatitis B and D may also spread through contact with other body fluids. This contact can occur in many ways, including sharing drug needles or having unprotected sex.

The hepatitis A and E viruses typically cause only acute, or short-term, infections. In an acute infection, your body is able to fight off the infection and the virus goes away.

The hepatitis B, C, and D viruses can cause acute and chronic, or long-lasting, infections. Chronic hepatitis occurs when your body isn’t able to fight off the hepatitis virus and the virus does not go away. Chronic hepatitis can lead to complications such as cirrhosis, liver failure, and liver cancer NIH external link. Early diagnosis and treatment of chronic hepatitis can prevent or lower your chances of developing these complications.

When doctors can’t find the cause of a person’s hepatitis, they may call this condition non-A–E hepatitis or hepatitis X. Experts think that unknown viruses other than hepatitis A, B, C, D, and E may cause some cases of hepatitis. Researchers are working to identify these viruses.

Although non-A–E hepatitis is most often acute, it can become chronic.

Solution: D

Metamaterial, an artificially structured material that exhibits extraordinary electromagnetic properties not available or not easily obtainable in nature. Since the early 2000s, metamaterials have emerged as a rapidly growing interdisciplinary area, involving physics, electrical engineering, materials science, optics, and nanoscience.

The properties of metamaterials are tailored by manipulating their internal physical structure. This makes them remarkably different from natural materials, whose properties are mainly determined by their chemical constituents and bonds. The primary reason for the intensive interest in metamaterials is their unusual effect on light propagating through them.

Solution: D

The Cabinet Committee on Economic Affairs chaired by the Prime Minister Shri Narendra Modi has approved ‘Natural Gas Marketing Reforms’, taking another significant step to move towards gas based economy.

The objective of the policy is to prescribe standard procedure to discover market price of gas to be sold in the market by gas producers, through a transparent and competitive process, permit Affiliates to participate in bidding process for sale of gas and allow marketing freedom to certain Field Development Plans (FDPs) where Production Sharing Contracts already provide pricing freedom.

Source: Yojana, November, 2020

Solution: B

The Union Cabinet in July 2020 has approved a new pan India Central Sector Scheme called Agriculture Infrastructure Fund.

Hence, statement 1 is incorrect.

The scheme shall provide a medium – long term debt financing facility for investment in viable projects for post-harvest management Infrastructure and community farming assets through interest subvention and financial support.

Hence, statement 2 is correct.

The duration of the Scheme shall be from FY2020 to FY2029 (10 years).

Under the scheme, Rs. One Lakh Crore will be provided by banks and financial institutions as loans to Primary Agricultural Credit Societies (PACS), Marketing Cooperative Societies, Farmer Producers Organizations (FPOs), Self Help Group (SHG), Farmers, Joint Liability Groups (JLG), Multipurpose Cooperative Societies, Agri-entrepreneurs, Startups, Aggregation Infrastructure Providers and Central/State agency or Local Body sponsored Public Private Partnership Project.

https://vikaspedia.in/schemesall/schemes-for-farmers/agriculture-infrastructure-fund

Source: Yojana, November 2020

Solution: A

The Monetary Policy Committee (MPC) is a committee of the Central Bank in India (Reserve Bank of India), headed by its Governor, which is entrusted with the task of fixing the benchmark policy interest rate (repo rate) to contain inflation within the specified target level.

Hence, statement 1 is correct.

Monetary Policy Committee is defined in Section 2(iii)(cci) of the Reserve Bank of India Act, 1934 and is constituted under Sub-section (1) of Section 45ZB of the same Act.

Hence, statement 2 is incorrect.

The MPC replaces the current system where the RBI governor, with the aid and advice of his internal team and a technical advisory committee, has complete control over monetary policy decisions. A Committee-based approach will add lot of value and transparency to monetary policy decisions.

The proceedings of MPC are confidential and the quorum for a meeting shall be four Members, at least one of whom shall be the Governor and in his absence, the Deputy Governor who is the Member of the MPC.

The MPC takes decisions based on majority vote (by those who are present and voting). In case of a tie, the RBI governor will have the second or casting vote. The decision of the Committee would be binding on the RBI.

Hence, statement 3 is correct.

http://www.arthapedia.in/index.php?title=Monetary_Policy_Committee_(MPC)

Solution: D

The Kisan credit card scheme aims at providing adequate and timely cred it for the comprehensive credit requirements of farmers under single window for their cultivation and other needs as indicated below:

• To meet the short term credit requirements for cultivation of crops
• Post harvest expenses
• Produce Marketing loan
• Consumption requirements of farmer household
• Working capital for maintenance of farm assets, activities allied to agriculture, like dairy animals, inland fishery and also working capital required for floriculture, horticulture etc.
• Investment credit requirement for agriculture and allied activities like pump sets, sprayers, dairy animals, floriculture, horticulture etc
• Short term credit requirements of rearing of animals, birds, fish, shrimp, other aquatic organisms, capture of fish.

Eligibility

• All farmers-individuals/Joint borrowers who are owner cultivators.
• Tenant farmers, Oral lessees and Share Croppers etc.
• SHGs or Joint Liability Groups of farmers including tenant farmers, share croppers etc.,
• The criteria for eligible beneficiaries under KCC for Animal Husbandry and Fisheries are as follows
  • Fishery
    • Inland Fisheries and Aquaculture – Fishers, Fish Farmers (individual & groups/ partners/ share croppers/ tenant farmers), Self Help Groups, Joint Liability Groups and women groups. The beneficiaries must own or lease any of the fisheries related activities such as pond, tank, open water bodies, raceway, hatchery, rearing unit, possess necessary license for fish farming and fishing related activities, and any other State specific fisheries and allied activities.
    • Marine Fisheries – Beneficiaries listed above, who own or lease registered fishing vessel/boat, possess necessary fishing license/permission for fishing in estuary and sea, fish farming/mariculture activities in estuaries and open sea and any other State specific fisheries and allied activities.
  • Poultry and small ruminant – Farmers, poultry farmers either individual or joint borrower, Joint Liability Groups or Self Help Groups including tenant farmer of sheep/goats/pigs/poultry/ birds /rabbit and having owned/rented/leased sheds.
  • Dairy – Farmers and Dairy farmers either individual or joint borrower, Joint Liability Groups or Self Help Groups including tenant farmers having owned /rented/leased sheds.

https://vikaspedia.in/agriculture/agri-credit/revised-kisan-credit-card-scheme

Source: Yojana, November, 2020

Solution: B

V-shaped recovery is a type of economic recession and recovery that resembles a “V” shape in charting. Specifically, a V-shaped recovery represents the shape of a chart of economic measures economists create when examining recessions and recoveries. A V-shaped recovery involves a sharp rise back to a previous peak after a sharp decline in these metrics.

Hence, statement 1 is incorrect.

A K-shaped recovery occurs when, following a recession, different parts of the economy recover at different rates, times, or magnitudes. This is in contrast to an even, uniform recovery across sectors, industries, or groups of people.

Hence, statement 2 is incorrect.

A W-shaped recovery involves a sharp decline in these metrics followed by a sharp rise back upward, followed again by a sharp decline and ending with another sharp rise. The middle section of the W can represent a significant bear market rally or a recovery that was stifled by an additional economic crisis.

Hence, statement 3 is correct.

Solution: D

Champion Services Sectors refers to the 12 identified sectors where the Government wants to give focused attention for promoting their development, and realizing their potential.

These include Information Technology & Information Technology enabled Services (IT& ITeS), Tourism and Hospitality Services, Medical Value Travel, Transport and Logistics Services, Accounting and Finance Services, Audio Visual Services, Legal Services, Communication Services, Construction and Related Engineering Services, Environmental Services, Financial Services and Education Services.

A dedicated fund of Rs. 5000 crores have been proposed to be established to support initiatives for sectoral Action Plans of the Champion Sectors.

Rationale and Objective

This initiative is expected to enhance the competitiveness of India’s service sectors thereby creating more jobs in India, contributing to a higher GDP and export of services to global markets.

Targets

The share of India’s services sector in global services exports was 3.3% in 2015. Based on this initiative, a goal of 4.2% has been envisaged for 2022. The share of services in Gross Value Added (GVA) was about 53% for India in 2015-16 (61% including construction services). This initiative is expected to raise the share of services in GVA to 60% (67% including construction services) by the year 2022.

http://www.arthapedia.in/index.php?title=Champion_Services_Sectors

Solution: A

About NIP:

When was it announced?

In the budget speech of 2019-2020, Finance Minister announced an outlay of Rs 100 lakh Crore for infrastructure projects over the next 5 years.

What is it?

1. NIP is a first-of-its-kind initiative to provide world-class infrastructure across the country and improve the quality of life for all citizens.

Hence, statement 1 is correct.

1. It will improve project preparation, attract investments (both domestic & foreign) into infrastructure, and will be crucial for attaining the target of becoming a $5 trillion economy by FY 2025.
2. Covers both economic and social infrastructure projects.

Hence, statement 2 is incorrect.

https://www.insightsonindia.com/2020/08/11/national-infrastructure-pipeline-nip/

Source: Yojana, November, 2020

Solution: C

Intergovernmental Panel on Climate Change (IPCC):

It is the United Nations body for assessing the science related to climate change.

Created in 1988 by the World Meteorological Organization(WMO) and the United Nations Environment Programme (UNEP), the objective of the IPCC is to provide governments at all levels with scientific information that they can use to develop climate policies. 

The IPCC is an organization of governments that are members of the United Nations or WMO. The IPCC currently has 195 members.

Through its assessments, the IPCC identifies the strength of scientific agreement in different areas and indicates where further research is needed. The IPCC does not conduct its own research.

https://www.ipcc.ch/about/

Source: Yojana, November 2020

Solution: B

Countries across the globe committed to create a new international climate agreement by the conclusion of the U.N. Framework Convention on Climate Change (UNFCCC) Conference of the Parties (COP21) in Paris in December 2015. In preparation, countries have agreed to publicly outline what post-2020 climate actions they intend to take under a new international agreement, known as their Intended Nationally Determined Contributions (INDCs). The INDCs will largely determine whether the world achieves an ambitious 2015 agreement and is put on a path toward a low-carbon, climate-resilient future.

India has submitted its Intended Nationally Determined Contribution (INDC) to the United Nations Framework Convention on Climate Change.

Salient features of India’s INDC

• To put forward and further propagate a healthy and sustainable way of living based on traditions and values of conservation and moderation.
• To adopt a climate-friendly and a cleaner path than the one followed hitherto by others at corresponding level of economic development.
• To reduce the emissions intensity of its GDP by 33 to 35 per cent by 2030 from 2005 level.
• To achieve about 40 per cent cumulative electric power installed capacity from non-fossil fuel based energy resources by 2030, with the help of transfer of technology and low cost international finance, including from Green Climate Fund.
• To create an additional carbon sink of 2.5 to 3 billion tonnes of CO₂ equivalent through additional forest and tree cover by 2030.
• To better adapt to climate change by enhancing investments in development programmes in sectors vulnerable to climate change, particularly agriculture, water resources, Himalayan region, coastal regions, health and disaster management.
• To mobilize domestic and new and additional funds from developed countries to implement the above mitigation and adaptation actions in view of the resource required and the resource gap.
• To build capacities, create domestic framework and international architecture for quick diffusion of cutting edge climate technology in India and for joint collaborative R&D for such future technologies.

https://vikaspedia.in/energy/environment/climate-change/indias-intended-nationally-determined-contribution

Source: Yojana, November 2020

Solution: B

75 tribal groups have been categorized by Ministry of Home Affairs as Particularly Vulnerable Tribal Groups (PVTG)s. PVTGs reside in 18 States and UT of A&N Islands.

The Ministry of Tribal Affairs implements the Scheme of “Development of Particularly Vulnerable Tribal Groups (PVTGs)” exclusively for them. Under the scheme, Conservation-cum-Development (CCD)/Annual Plans are to be prepared by each State/UT for their PVTGs based on their need assessment, which are then appraised and approved by the Project Appraisal Committee of the Ministry. Activities for development of PVTGs are undertaken in Sectors of Education, Health, Livelihood and Skill Development, Agricultural Development , Housing & Habitat, Conservation of Culture etc.

https://tribal.nic.in/pvtg.aspx

Solution: A

Mangroves

• Mangroves are trees or large shrubs which are salt-tolerant and grow in intertidal zones in tropical and subtropical regions
• Sundarbans is a mangrove area in the delta formed by the confluence of the Ganges, Brahmaputra and Meghna Rivers in the Bay of Bengal.
• It spans from the Hooghly River in India’s state of West Bengal to the Baleswar River in Bangladesh.

Benefits of Mangroves

• Diversity of mangrove roots and their position gives mangroves an important role as habitats for numerous species.
• Mangroves also act as a refuge for corals from ocean acidification
• Mangroves filter and trap sediment from run-off and river water before it reaches adjacent ecosystems.
• Reduces the turbidity of the water and allowing essential light to reach ecosystems
• Mangroves are among the most carbon-rich forests in the tropics. They help in carbon sequestration.
• Conservation and restoration of mangroves can therefore contribute significantly to climate change mitigation.
• Their ability to trap organic sediment and thus store carbon, they are referred to as ‘blue carbon’ sinks.
• Shoreline protection based on mangrove tree and root structures in reducing erosion.
• Food resources for animals such as migratory birds and fish
• Visual amenity where selected mangrove trees provide shoreline beautification.

The Mangrove ecosystems are unique & rich in biodiversity and they provide numerous ecological services. Mangrove cover has been separately reported in the ISFR 2019 and the total mangrove cover in the country is 4,975 sq km. An increase of 54 sq Km in mangrove cover has been observed as compared to the previous assessment of 2017. Top three states showing mangrove cover increase are Gujarat (37 sq km) followed by Maharashtra (16 sq km) and Odisha (8 sq km).

Solution: C

Dhole (Asiatic wild dog):

• The dhole is a canid native to Central, South, East, and Southeast Asia. Other English names for the species include Asian wild dog, Asiatic wild dog, Indian wild dog,
• It plays an important role as apex predators in forest ecosystems
• Wild dogs are highly adaptable to their environment and generally found in the deciduous, evergreen and the alpine steppes. Fewer than 3000 adults left in the wild, India perhaps sustains the highest number of dholes, which are widely distributed in three major landscapes- Western Ghats, Central India and Northeast India.

Habitat:

Dhole is a habitat generalist, and can occur in a wide variety of vegetation types, including: primary, secondary and degraded forms of tropical dry and moist deciduous forests; evergreen and semi-evergreen forests; temperate deciduous forests; boreal forests; dry thorn forests; grassland–scrub–forest mosaics; temperate steppe; and alpine steppe

Threats:

• Depletion of prey base
• Habitat loss and transformation
• Persecution of Dholes stems mainly from retaliatory killings due to livestock predation
• Disease and pathogens: Dholes are susceptible to rabies, canine distemper, canine parvovirus and sarcoptic mange among others which are usually contracted from domestic village dogs that act as reservoirs.
• Competition with other species like Tigers and Leopards for prey

Solution: D

Snow leopard:

• They are listed as Vulnerable on the IUCN Red List of Threatened Species.
• They inhabit alpine and subalpine zones at elevations from 3,000 to 4,500 m (9,800 to 14,800 ft). In the northern range countries, they also occur at lower elevations.
• The snow leopard is the state animal of Uttarakhand and the National Heritage Animal of Pakistan.
• Their habitat extends through twelve countries: Afghanistan, Bhutan, China, India, Kazakhstan, Kyrgyzstan, Mongolia, Nepal, Pakistan, Russia, Tajikistan, and Uzbekistan. China contains as much as 60% of all snow leopard habitat areas.
• In India, their geographical range encompasses a large part of the western Himalayas including the states of Jammu and Kashmir, Himachal Pradesh, Uttarakhand and Sikkim and Arunachal Pradesh in the eastern Himalayas.
• The snow leopard, like all big cats, is listed on Appendix I of the Convention on International Trade of Endangered Species (CITES), which makes trading of animal body parts (i.e., fur, bones and meat) illegal in signatory countries. It is also protected by several national laws in its range countries.
• Global Snow Leopard Forum, 2013: 12 countries encompassing the snow leopard’s range (Afghanistan, Bhutan, China, India, Kazakhstan, Kyrgyz Republic, Mongolia, Nepal, Pakistan, Russia, Tajikistan, and Uzbekistan).
• Bishkek Declaration: To protect the species and it’s environment.
• Global Snow Leopard and Eco-system Protection Program: It is a joint initiative of range country governments, international agencies, civil society, and the private sector. Goal — secure the long-term survival of the snow leopard in its natural ecosystem.

Snow leopards are distributed across the 100,146 sq. km of snowy forests in five Himalayan states – Jammu & Kashmir, Uttarakhand, Himachal Pradesh, Sikkim & Arunachal Pradesh.
Hemis National Park, Gangotri National Park, Khangchendzonga National park, Namdapha National Park and Great Himalayan National Park are some protected areas where snow leopards are known to be found.

Solution: B

Eravikulam National Park:

• Eravikulam National Park is a 97 km national park located along the Western Ghats in the Idukki and Ernakulam district of Kerala in India.
• It was declared a Sanctuary in 1975 with the intention of protecting the indigenous population of Nilgiri Tahr and declared as a National Park in 1978.
  • The Nilgiri tahr is found in its largest viable population in the Eravikulam National Park, one the last and safest refuges of the highly-endangered mountain goat
• This is also the land of “Neelakurinji”, a flower that blooms once in twelve years.
• Anamudi (2695 m), South India’s highest peak is situated in this park.
• Three major types of plant communities found in the park are: Grasslands, Shrub Land and Shola Forests.

Solution: A

International Labour Organization:

• Established as an agency for the League of Nations following World War I.
• Established by the Treaty of Versailles in 1919.
• It became the first specialised agency of the United Nations (UN) in the year 1946.
• It got the Nobel Peace Prize in 1969.
• It is the only tripartite U.N. agency. It brings together governments, employers and workers.
• Headquarters: Geneva, Switzerland.

India has ratified six out of the eight-core/fundamental ILO conventions.  India has not ratified the two core/fundamental conventions, namely Freedom of Association and Protection of the Right to Organise Convention, 1948 (No. 87) and Right to Organise and Collective Bargaining Convention, 1949 (No. 98).

Key reports:

• World Employment and Social Outlook.
• Global Wage Report.

Solution: B

Relative Speed of trains when moving in same direction = (60 -40) kmph = 20 * 5/18 = 100/18 m/s

Time = 50 sec
Total Distance = Relative Speed * Time = 100/18 * 50 = 2500/9 m
Relative Speed when moving in opposite direction = (60 + 40) kmph = 100 * 5/18 m/s = 500/18 m/s
Therefore, Time taken = Distance/Speed = 2500/9 * 18/500 = 10 sec

Solution: B

Work done by A, B and C together in one day = 1/5

Work done by A and B in one day = 1/7

Therefore, work done by C alone in one day = 1/5 – 1/7 = 2/35

Therefore, total time taken by C alone to complete the work = 35/2 days or 17.5 days.

Solution: B

Let the two numbers be 2x and 3x

Therefore (2x)³ + (3x)³ = 945

Or 8x³+ 27x³ = 945

Or x³ = 945/35 = 27

Therefore, x= 3

Difference between two numbers = 3x – 2x =x

Or Difference = 3

Solution: D

Let two numbers be x and y.

It is given that, y – x/4 = 5y/6

Therefore, y- 5y/6 = x/4

Or y/6 = x/4

Therefore, x/y = 4/6 or 2:3 

Ans. B.

The focus of the passage is on explaining how the plastic waste management rules have not proven effective and what more can be done by municipal committees in this regard. Hence B is the most accurate and critical inference.