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All questions of Week 7 for UGC NET Exam

Statement 1: All chickens are birds.
Statement 2: Some chickens are hens.
Statement 3: Female birds lay eggs.
If the above statement are facts, then which of the following must also be a fact?
I. All birds lay eggs.
II. Hens are birds.
III. Some chickens are not hens.
  • a)
    II only
  • b)
    II and III only
  • c)
    I, II and III
  • d)
    None of the statement is a known fact
Correct answer is option 'D'. Can you explain this answer?

Statements I and II can be represented as venn diagrams in the following ways:
As ‘Female birds lay eggs’, so ‘All birds lay eggs’ is incorrect.
Conclusion ‘Hens are Birds’ may or may not be true as can be seen from the Venn diagrams.
Conclusion ‘Some chickens are not hens’ is also not definitely true as can be seen from the third Venn diagram.
Hence, option (d).

A vessel is full of a mixture of methanol and ethanol in which there is 20% ethanol. 10 litres of mixture are drawn off and filled with methanol. If the ethanol is now 15%, what is the capacity of the vessel?
  • a)
    40l
  • b)
    30l
  • c)
    50l
  • d)
    36l
Correct answer is option 'A'. Can you explain this answer?

Arnav Desai answered
Problem:
A vessel is full of a mixture of methanol and ethanol in which there is 20% ethanol. 10 litres of mixture are drawn off and filled with methanol. If the ethanol is now 15%, what is the capacity of the vessel?

Solution:
Let us assume that the vessel has a capacity of x liters.

Initial Mixture:
Initially, the mixture in the vessel contains 20% ethanol.
So, the amount of ethanol in the initial mixture = (20/100) * x = 0.2x liters.
And, the amount of methanol in the initial mixture = (80/100) * x = 0.8x liters.

When 10 liters of the initial mixture is drawn off, the amount of ethanol and methanol in the mixture will be:

Ethanol: (20/100) * 10 = 2 liters
Methanol: (80/100) * 10 = 8 liters

After drawing off 10 liters of the mixture, the vessel contains (x - 10) liters of the initial mixture.

Now, 10 liters of methanol is added to the mixture. So, the amount of methanol in the mixture will be:

Methanol: 8 + 10 = 18 liters

And, the amount of ethanol in the mixture will remain the same, i.e., 2 liters.

Final Mixture:
The final mixture contains 15% ethanol.
So, the amount of ethanol in the final mixture = (15/100) * x liters.
And, the amount of methanol in the final mixture = (85/100) * x liters.

We know that the amount of ethanol in the final mixture is (amount of ethanol in the initial mixture - 10 + 0) liters.

So, we can write the equation:

(15/100) * x = 0.2x - 10

Solving this equation, we get:

x = 40 liters

Therefore, the capacity of the vessel is 40 liters.

Answer: (a) 40 liters

Each of these questions given below contains three elements. These elements may or may not have some inter linkage. Each group of elements may fit into one of these diagrams at (A), (B), (C), (D) and/or (E). You have to indicate the group of elements which correctly fits into the diagrams.
Q.
Which of the following diagrams indicates the best relation between Travelers, Train and Bus ?
  • a)
  • b)
  • c)
  • d)
Correct answer is option 'C'. Can you explain this answer?

Iq Funda answered
The best relation between Travelers, Train, and Bus can be represented in a Venn diagram, where Travelers are represented as a larger circle containing both Train and Bus circles. This is because travelers can choose either train or bus as their mode of transportation, and some may use both. Here's the explanation:
Travelers
- Travelers are people who move from one place to another for various reasons, such as work, leisure, or other purposes.
Train
- A train is a mode of transportation that runs on a railway track and can carry passengers or goods.
- Some travelers may choose to travel by train due to various factors such as cost, comfort, or availability.
Bus
- A bus is a mode of transportation that runs on roads and can carry passengers.
- Some travelers may choose to travel by bus due to factors such as cost, convenience, or accessibility.
Venn Diagram: Option C
- In option C, we have a large circle representing Travelers, which includes two smaller circles representing Train and Bus.
- This diagram shows that there are travelers who use trains, travelers who use buses, and some travelers who may use both modes of transportation.
- This representation captures the relationship between travelers and their choice of transportation, whether it's by train, bus, or both.

In the question given below, there are two statements marked as Assertion (A) and Reason (R). Read the statements and chose the correct option:
Assertion (A) : Earth is the only planet known to have life.
Reason (R) : Earth has no atmosphere which is a mixture of oxygen, nitrogen and carbon dioxide.
  • a)
    A is true but R is false.
  • b)
    Both A and R are true and R is the correct explanation of A.
  • c)
    Both A and R are true but R is not the correct explanation of A.
  • d)
    A is false but R is true.
  • e)
    Both A and R are false.
Correct answer is option 'A'. Can you explain this answer?

Assertion and Reasoning

Assertion (A): Earth is the only planet known to have life.
Reasoning (R): Earth has no atmosphere which is a mixture of oxygen, nitrogen, and carbon dioxide.

Explanation:

This is an assertion and reasoning type question. Let's analyze the given statements one by one.

Assertion (A): Earth is the only planet known to have life.

The assertion is correct. To date, no other planet has been discovered that has life on it. Earth is unique in that it has the right combination of factors such as the right distance from the sun, a suitable atmosphere, and a magnetic field that protects it from solar winds, which makes it capable of sustaining life.

Reasoning (R): Earth has no atmosphere which is a mixture of oxygen, nitrogen, and carbon dioxide.

The reasoning is incorrect. Earth's atmosphere is a mixture of several gases including oxygen, nitrogen, and carbon dioxide. These gases provide the necessary conditions for life to exist on Earth. Oxygen, for instance, is essential for respiration, while nitrogen is needed for the synthesis of amino acids, the building blocks of proteins, which are essential for life.

Therefore, both the assertion and reasoning are true, but the reasoning does not explain the assertion. The correct answer is option (A).

Each of the questions below starts with a few statements, followed by four conclusions numbered 1, 2, 3 and 4.  You have to consider every given statement as true, even if it does not conform to the accepted facts.  Read the conclusions carefully and then decide which of the conclusion(s) logically follow(s) from the given statements, disregarding commonly known facts.
Statements:
a. Some boys are scholars
b. Some teachers are boys
c. All scholars are observers
Conclusions:
1. Some scholars are boys
2. Some scholars are not boys
3. Some observers are boys
4. Some teachers are scholars
  • a)
    1, and 3 follow
  • b)
    1, 3, and 4 follow
  • c)
    Either 1 or 2 and 3 follow
  • d)
    None of the above
Correct answer is option 'A'. Can you explain this answer?

Answer: Option A
Some boys are scholars: 
There are two possible deductions from this statement.
i) All scholars are boys (i.e. the set of scholars is a subset of boys)
ii) Some scholars are boys (i.e. the intersection of the sets of scholars and boys is not a null set)
Some teachers are boys
There are two possible deductions from this statement.
i) All boys are teachers (i.e. the set of boys is a subset of teachers)
ii) Some boys are teachers (i.e. the intersection of the sets of teachers and boys is not a null set)
All scholars are observers.
There are two possible deductions from this statement.
i) All observers are scholars (i.e. the set of observers and scholars are identical)
ii) Some observers are scholars (i.e. the set of observers is a subset of scholars)
Let us analyze the conclusions:
1) Some scholars are boys.This is true for both the cases that have been mentioned above,
2) Some scholars are not boysThis may or may not be true because there are chances that all scholars may also be boys.
3) Some observers are boys.We know that either all or some observers are scholars (i.e. the set of observers is definitely a subset of the set of scholars) and the intersection of the sets of scholars and boys is not a null set. This means that some observers will always be boys. Hence conclusion 3 is true.
4) Some teachers are scholars.The intersection of set of boys and scholars is not a null set and the intersection of set of boys and teachers is not a null set. But this doesn’t mean that the intersection of boys and teachers will also be a null set. There may or may not be some teachers who are scholars.
Thus this statement is incorrect.

In the question given below, there are two statements marked as Assertion (A) and Reason (R). Read the statements and chose the correct option:
Assertion (A) : There is rainbow in the sky only after rains.
Reason (R) : Water drops suspended in the air break up sun’s rays into seven colours.
  • a)
    Both A and R are true and R is the correct explanation of A.
  • b)
    Both A and R are true but R is not the correct explanation of A.
  • c)
    A is true but R is false.
  • d)
    A is false but R is true.
  • e)
    Both A and R are false.
Correct answer is option 'A'. Can you explain this answer?

Ruchi Reddy answered
The correct option is:

A) Assertion (A) is true, but Reason (R) is false.

Explanation:

Assertion (A) states that there is a rainbow in the sky only after rains. This statement is true because raindrops act as tiny prisms that refract and reflect sunlight, creating the optical phenomenon known as a rainbow.

Reason (R) states that water drops suspended in the air break up sun. This statement is false because water droplets do not break up the sun. Instead, they act as a medium for the dispersion and refraction of sunlight, which leads to the formation of a rainbow.

In the question given below, there are two statements marked as Assertion (A) and Reason (R). Read the statements and chose the correct option:
Assertion (A): Passengers in a boat are not allowed to stand.
Reason (R): This may raise the centre of gravity of the boat .
  • a)
    A is true but R is false.
  • b)
    A is false but R is true.
  • c)
    Both A and R are false.
  • d)
    Both A and R are true but R is not the correct explanation of A.
  • e)
    Both A and R are true and R is the correct explanation of A.
Correct answer is option 'E'. Can you explain this answer?

In this case, both Assertion (A) and Reason (R) are true. The correct option is e) Both A and R are true and R is the correct explanation of A.
It is generally not allowed for passengers in a boat to stand, because this can raise the center of gravity of the boat, which can cause the boat to become unstable and potentially tip over. This is the correct explanation of why passengers are not allowed to stand in a boat.

Which of the following are accepted in Buddhism?
A. Adhyasa
B. Apoha
C. Abhava
D. Arthapatti
E. Pratyaiksha
F. Sabada
Choose the correct answer from the options given below:
  • a)
    A and B only
  • b)
    C and D only
  • c)
    B and E only
  • d)
    E and F only
Correct answer is option 'C'. Can you explain this answer?

JKL Classes answered
Apoha:
  • Apoha refers to the Buddhist “exclusion theory”
  • It is a negative process of exclusion
  • Apoha or exclusions can be used to explain away universals as the referents of words.
Pratyaksa:
  • Pratyaksa means the perception both internal and external.
  • The knowledge is perceptible to the eye or visible and recognizable through other sensory organs and the mind.
  • Eye, ear, nose, tongue, and skin are the five sensory organs and mine is the sixth one.

In the question given below, there are two statements marked as Assertion (A) and Reason (R). Read the statements and chose the correct option:
Assertion (A) : An atom is neutral despite the charged particles in it.
Reason (R) : The neutrons do not have any charge.
  • a)
    Both A and R are true but R is not the correct explanation of A.
  • b)
    Both A and R are true and R is the correct explanation of A.
  • c)
    A is false but R is true.
  • d)
    A is true but R is false.
  • e)
    Both A and R are false.
Correct answer is option 'A'. Can you explain this answer?

Malavika Joshi answered
Explanation:
Assertion (A) and Reason (R) Analysis:
- Assertion (A): An atom is neutral despite the charged particles in it.
- Reason (R): The neutrons do not have any charge.
Explanation of Correct Answer:
- Both assertion (A) and reason (R) are true.
- The assertion is correct because an atom contains equal numbers of protons and electrons, which are positively and negatively charged particles respectively. This balance of charges makes the atom electrically neutral.
- The reason is also true as neutrons, the neutral subatomic particles found in the nucleus of an atom, do not have any charge. Their presence does not contribute to the overall charge of the atom.
- The reason provided indeed explains why the assertion is true. Neutrons being neutral help in maintaining the overall neutrality of the atom despite the presence of charged particles like protons and electrons.
Therefore, option 'A' is the correct choice where both assertion (A) and reason (R) are true, but reason (R) is not the correct explanation of assertion (A).

Each of the questions below starts with a few statements, followed by four conclusions numbered 1, 2, 3 and 4.  You have to consider every given statement as true, even if it does not conform to the accepted facts.  Read the conclusions carefully and then decide which of the conclusion(s) logically follow(s) from the given statements, disregarding commonly known facts.
Statements:
a. All teachers are professors
b. All professors are researchers
c. All researchers are consultants
Conclusions:
1. Some consultants are teachers
2. All professors are consultants
3. Some researchers are teachers
4. All professors are teachers
  • a)
    Only 1 and 2 follow
  • b)
    Only 1 and 3 follow
  • c)
    Either 1 or 4 follow
  • d)
    None of the above
Correct answer is option 'D'. Can you explain this answer?

Samaira nayar answered
Analysis:
All teachers are professors, all professors are researchers, and all researchers are consultants. We have to determine which conclusions logically follow from these given statements.

Conclusions:

1. Some consultants are teachers
This conclusion can be logically derived from the given statements. Since all teachers are professors, and all professors are researchers, which in turn are consultants, it is possible that some consultants are also teachers.

2. All professors are consultants
This conclusion cannot be logically derived from the given statements. While all professors are indeed researchers and consultants, it does not necessarily mean that all professors are consultants. The statements do not provide a direct link between professors and consultants.

3. Some researchers are teachers
This conclusion can be logically derived from the given statements. Since all professors are researchers, and all teachers are professors, it is possible that some researchers are also teachers.

4. All professors are teachers
This conclusion cannot be logically derived from the given statements. Although all teachers are professors, it does not mean that all professors are teachers. The statements only establish a one-way relationship between teachers and professors, not vice versa.
Therefore, only conclusions 1 and 3 logically follow from the given statements.

290 students of MBA (International Business) in a reputed Business School have to study foreign language in Trimesters IV and V. Suppose the following information are given
(i) 120 students study Spanish
(ii) 100 students study Mandarin
(iii) At least 80 students, who study a foreign language, study neither Spanish nor Mandarin
Then the number of students who study Spanish but not Mandarin could be any number from
  • a)
    20 to 110
  • b)
    80 to 100
  • c)
    50 to 80
  • d)
    80 to 170
Correct answer is option 'A'. Can you explain this answer?

G.K Academy answered
Atleast 80 students study neither Spanish nor Mandarin.
Hence, maximum number of students who study atleast one language = 290 – 80 = 210
Minimum number of students who study both languages = 100 + 120 – 210 = 10
∴ Maximum number of students who study Spanish but not Mandarin = 120 – 10 = 110
Maximum number of students who study both languages = smaller value of 100 and 120 = 100
∴ Minimum number of students who study Spanish but not Mandarin = 120 – 100 = 20
Hence, the range could be any number from 20 to 110.
Hence, option (a).

Directions to Solve
In each of the following questions two statements are given and these statements are followed by two conclusions numbered (1) and (2). You have to take the given two statements to be true even if they seem to be at variance from commonly known facts. Read the conclusions and then decide which of the given conclusions logically follows from the two given statements, disregarding commonly known facts.
Give answer:
  • (A) If only (1) conclusion follows
  • (B) If sonly (2) conclusion follows
  • (C) If either (1) or (2) follows
  • (D) If neither (1) nor (2) follows and
  • (E) If both (1) and (2) follow.
Question -
Statements: All the windows are doors. No door is a wall.
Conclusions:
  1. Some windows are walls.
  2. No wall is a door.
  • a)
    Only (1) conclusion follows
  • b)
    Only (2) conclusion follows
  • c)
    Either (1) or (2) follows
  • d)
    Neither (1) nor (2) follows
  • e)
    Both (1) and (2) follow
Correct answer is option 'B'. Can you explain this answer?

Mainak Saha answered
Understanding the Statements
The given statements are:
- All the windows are doors.
- No door is a wall.
Analyzing the Conclusions
1. Conclusion 1: Some windows are walls.
- Since all windows are classified as doors and no door can be a wall, it's impossible for any window to be a wall. Therefore, this conclusion does not logically follow from the statements.
2. Conclusion 2: No wall is a door.
- Given that no door is a wall, this statement is essentially a restatement of the second premise. Thus, it logically follows from the statements provided.
Final Evaluation
- Conclusion 1: Does not follow.
- Conclusion 2: Follows.
Answer Selection
Based on the analysis:
- Only conclusion (2) logically follows from the statements provided.
Thus, the correct answer is (B) Only (2) conclusion follows.

In the question given below, there are two statements marked as Assertion (A) and Reason (R). Read the statements and chose the correct option:
Assertion (A) : Amoebiasis is an occupational disease.
Reason (R) : Amoebiasis is caused by inhalation of asbestos duet.
  • a)
    Both A and R are true and R is the correct explanation of A.
  • b)
    Both A and R are true but R is not the correct explanation of A.
  • c)
    A is true but R is false.
  • d)
    A is false but R is true.
  • e)
    Both A and R are false.
Correct answer is option 'E'. Can you explain this answer?

Bhavya Saha answered
Explanation:

Assertion (A) : Amoebiasis is an occupational disease.
- Amoebiasis is not classified as an occupational disease. It is a parasitic infection caused by the protozoan parasite Entamoeba histolytica.
- It is mainly transmitted through contaminated food and water, not through occupational exposure.

Reason (R) : Amoebiasis is caused by inhalation of asbestos dust.
- This statement is incorrect. Asbestos exposure is linked to respiratory diseases like asbestosis and lung cancer, not amoebiasis.
- Amoebiasis is caused by ingestion of the cysts of the parasite, not through inhalation of asbestos dust.
Therefore, both Assertion (A) and Reason (R) are false. Amoebiasis is not an occupational disease, and it is not caused by inhalation of asbestos dust.

In the question given below, there are two statements marked as Assertion (A) and Reason (R). Read the statements and chose the correct option:
Assertion (A) : Leakages in household gas cylinders can be detected.
Reason (R) : LPG has a strong smell.
  • a)
    Both A and R are true and R is the correct explanation of A.
  • b)
    Both A and R are true but R is not the correct explanation of A.
  • c)
    A is true but R is false.
  • d)
    A is false but R is true.
  • e)
    Both A and R are false.
Correct answer is option 'C'. Can you explain this answer?

Ishaan Kapoor answered
Assertion (A) : Leakages in household gas cylinders can be detected.
Reason (R) : LPG has a strong smell.

The correct option for this question is option 'C', which states that Assertion (A) is true but Reason (R) is false.

Explanation:

Assertion (A) : Leakages in household gas cylinders can be detected.
This statement is true. Leakages in household gas cylinders can indeed be detected through various means. Gas cylinders are designed with safety features to detect and prevent leakages. Some common methods to detect gas leaks include:

1. Smell: LPG (liquefied petroleum gas), which is commonly used in household gas cylinders, has a strong smell added to it. This is done intentionally to help people detect gas leaks easily. If there is a gas leakage, the strong smell of LPG becomes noticeable, alerting people to the danger.

2. Sound: Gas leaks can also be detected by listening for a hissing sound. If there is a leakage, gas escapes from the cylinder, creating a distinct sound that can be heard.

3. Soap Water Test: Another method to detect gas leaks is by using the soap water test. This involves applying a soapy solution to the gas cylinder valve and checking for the formation of bubbles. If bubbles form, it indicates a gas leak.

4. Gas Detectors: Gas detectors are devices specifically designed to detect the presence of gas leaks. These detectors use sensors to detect the gas concentration in the air and trigger an alarm if it exceeds a certain threshold.

Therefore, it is clear that leakages in household gas cylinders can be detected through various means.

Reason (R) : LPG has a strong smell.
This statement is false. LPG does not have a strong smell naturally. In its pure form, LPG is odorless and colorless. However, to ensure safety, a strong odorant called ethanethiol is added to LPG. This odorant gives LPG its characteristic smell, making it easier to detect gas leaks. Without the added odorant, it would be difficult to detect gas leaks as LPG is otherwise odorless.

Hence, the reason given is incorrect as LPG does not naturally have a strong smell.

In a syllogism, what term appears as a predicate in premise 1 and in the conclusion, while the middle term appears as a subject in premise 1 and as a predicate in premise 2?
  • a)
    Major term
  • b)
    Minor term
  • c)
    Middle term
  • d)
    Conclusion term
Correct answer is option 'A'. Can you explain this answer?

Academia Elite answered
The major term in a syllogism appears as a predicate in premise 1 and in the conclusion. On the other hand, the middle term appears as a subject in premise 1 and as a predicate in premise 2. Understanding the roles of major, minor, and middle terms in a syllogism is crucial for effectively analyzing and constructing logical arguments.

Which type of argument guarantees the truth of the conclusion based on the truth of the premises?
  • a)
    Inductive Argument
  • b)
    Abductive Argument
  • c)
    Deductive Argument
  • d)
    Hypothetical Argument
Correct answer is option 'C'. Can you explain this answer?

Academia Elite answered
In a deductive argument, the truth of the conclusion is guaranteed by the truth of the premises. This means that if the premises are true, the conclusion logically follows and must also be true. Deductive reasoning is characterized by this strong connection between premises and conclusions, ensuring the validity of the argument.

What kind of relationship in the square of opposition exists between propositions that vary in both quality and quantity, ensuring that if one is true, the other must be false?
  • a)
    Contradictory
  • b)
    Subalterns
  • c)
    Contraries
  • d)
    Sub-Contrary
Correct answer is option 'A'. Can you explain this answer?

Divit Mehra answered
Understanding the Square of Opposition
The square of opposition is a diagram representing the relationships between different types of categorical propositions. It consists of four corners representing four types of propositions based on quality (affirmative or negative) and quantity (universal or particular).
Contradictory Propositions
- Contradictory propositions are those that cannot both be true at the same time, nor can they both be false.
- They are positioned diagonally in the square of opposition. For example:
- Universal affirmative (All S are P) and particular negative (Some S are not P) are contradictory.
- If one is true, the other must be false.
Variations in Quality and Quantity
- The propositions that vary in both quality (affirmative vs. negative) and quantity (universal vs. particular) lead to contradictions.
- For instance:
- If "All cats are mammals" (universal affirmative) is true, then "Some cats are not mammals" (particular negative) must be false.
Why Option A is Correct
- The correct answer is option 'A' because contradictory relationships highlight the exclusive nature of truth values between propositions.
- This ensures that the truth of one directly negates the truth of the other, fulfilling the criteria of varying in both quality and quantity.
Conclusion
In summary, contradictory propositions in the square of opposition represent fundamental logical relationships, where the truth of one proposition guarantees the falsehood of another. Understanding this relationship is crucial for studying logical reasoning and argumentation in the UGC NET context.

What defines the structure of a logical argument?
  • a)
    A set of conclusions drawn from premises
  • b)
    A set of premises leading to a conclusion
  • c)
    A set of hypotheses supporting an outcome
  • d)
    A set of contradictory statements
Correct answer is option 'B'. Can you explain this answer?

Academia Elite answered
The structure of a logical argument is defined by a set of premises that lead to a conclusion. Premises are statements that provide the foundation for the conclusion, and the conclusion is drawn based on the reasoning from these premises. This structure forms the basis of a logical argument, where the conclusion is supported by the premises provided.

Read the given statements and conclusions carefully. Assuming that the information given in the statements is true, even if it appears to be at variance with commonly known facts, decide which of the given conclusions logically follow(s) from the statements.
Statements:
No plate is a spoon.
Some plates are forks.
All forks are knives.
Conclusions:
I. Some plates are knives is a possibility.
II. No spoon is a fork.
  • a)
    Only conclusion I follows
  • b)
    Neither conclusion I nor II follows
  • c)
    Both conclusions I and II follow
  • d)
    Only conclusion II follows
Correct answer is option 'B'. Can you explain this answer?

EduRev CLAT answered
Statement:
No plate is a spoon.
Some plates are forks.
All forks are knives.
The least possible diagram for the given statements is as follows:
Conclusions:
(i) Some plates are knives is a possibility - False (Some plates are forks and All forks are knives, so some plates are knives is definitely true).
(ii) No spoon is a fork - False (Because No direct relation given between them, so It can be possible not definite).
Here, Neither conclusion I nor II follows.
Hence, the correct answer is "Option 2".

In the question given below, there are two statements marked as Assertion (A) and Reason (R). Read the statements and chose the correct option:
Assertion (A): DDT has nowadays lost its use as an insecticide.
Reason (R) : DDT has harmful to man.
  • a)
    Both A and R are true and R is the correct explanation of A.
  • b)
    Both A and R are true but R is not the correct explanation of A.
  • c)
    A is true but R is false.
  • d)
    A is false but R is true.
  • e)
    Both A and R are false.
Correct answer is option 'B'. Can you explain this answer?

Swati Bajaj answered
Assertion (A): DDT has nowadays lost its use as an insecticide.
Reason (R): DDT has harmful to man.


The correct answer is option 'B': Both A and R are true but R is not the correct explanation of A.


Explanation:

DDT and its Use as an Insecticide:
DDT, short for dichlorodiphenyltrichloroethane, is a synthetic pesticide that was widely used as an insecticide in the past. It was highly effective in controlling pests and played a significant role in reducing the spread of diseases like malaria and typhus.

Loss of Use:
However, over time, DDT has lost its popularity and is no longer widely used as an insecticide. There are several reasons for this decline in usage:

1. Environmental Impact: DDT is a persistent organic pollutant. It does not easily break down in the environment and can accumulate in the food chain. This poses a significant threat to wildlife, particularly birds and fish. The harmful effects of DDT on birds, including thinning of eggshells, were observed, leading to population decline.

2. Resistance Development: Prolonged and widespread use of DDT led to the development of insecticide resistance in many pest species. This means that the insects have become less susceptible to the effects of DDT, making it less effective in controlling them.

3. Health Concerns: DDT has been linked to various health issues in humans. Although it was initially considered safe and widely used for pest control, studies have shown that long-term exposure to DDT can have adverse effects on human health. It has been associated with reproductive and developmental problems, as well as certain types of cancer.

Harmful to Humans:
The Reason (R) states that DDT is harmful to humans. This statement is true. While DDT was used extensively in the past, its harmful effects on human health have become a cause for concern. Prolonged exposure to DDT has been associated with various health issues, including:

1. Reproductive and Developmental Problems: DDT has been linked to adverse effects on reproductive health, such as infertility, miscarriages, and birth defects. It can disrupt hormone function and interfere with normal reproductive processes.

2. Cancer Risk: Studies have shown a potential link between DDT exposure and certain types of cancer, including breast cancer and non-Hodgkin's lymphoma.

3. Endocrine Disruption: DDT is known to disrupt the endocrine system, which regulates hormone production and function in the body. This can lead to hormonal imbalances and associated health problems.

However, it is important to note that the Reason (R) does not provide a correct explanation for the Assertion (A). The loss of use of DDT as an insecticide is primarily due to environmental concerns, resistance development, and regulatory restrictions. While the harmful effects on human health contribute to its decline in usage, they are not the sole reason for it. Hence, option 'B' is the correct answer.

In the following question below are given some statements followed by some conclusions based on those statements. Taking the given statements to be true even if they seem to be at variance from commonly known facts. Read all the conclusions and then decide which of the given conclusion logically follows the given statements.
Statements:
I. All B are V.
II. All K are B.
Conclusion:
I. All K are V.
II. No V is B.
  • a)
    Both conclusions I and II follows
  • b)
    Neither conclusion follows
  • c)
    Only conclusion I follows
  • d)
    Only conclusion II follows
Correct answer is option 'C'. Can you explain this answer?

Given Statements:
I. All B are V.
II. All K are B.

Conclusion:
I. All K are V.
II. No V is B.

Explanation:
In the given statements, it is mentioned that all B are V (I) and all K are B (II). Based on these statements, we can logically deduce the following:

Conclusion I: All K are V
Since all B are V and all K are B, it implies that all K are also V. This conclusion logically follows from the given statements.

Conclusion II: No V is B
This conclusion does not follow from the given statements. It is possible for some B to be V as per the first statement "All B are V".
Therefore, the correct answer is option C) Only conclusion I follows.

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