Shortcuts in Reasoning for Competitive Exams – Evaluating Inferences
This chapter makes you aware about a special type of question pattern which has become a regular trend of almost all type of competitive examination. An inference is a logical conclusion on evidence. A valid inference is believable and realistic. As per the pattern, a passage is given followed by some inferences (conclusions) and the examinee is asked to decide whether a given inference follows or not in the light of the given passage. Let us see the format below:
What is the problem like?
Problem Format/ Sample Problem:-
Directions (Q 1-5): Below is given a passage followed by several possible inferences which can be drawn from the facts stated in the passage. You have to examine each inference separately in the context of the passage and decide upon its degree of truth or falsity.
- If the inference is definitely true i. e., it properly follows from the statement of facts given.
- If the inference is ‘probably true’ though not definitely true in the light of the facts given.
- If the ‘data are inadequate’ i.e. from the facts given you can not say whether the inference is likely to be true or false.
- If the inference is ‘Probably false’ though not definitely false’ in the light of the facts given.
- If the inference is ‘definitely false’
i. e., it cannot possibly be drawn from the facts given or it contradicts the given facts.
In its most ambitions bid ever to house 6 crore slum dwellers and realise the vision of a slum-free India, the government is rolling out a massive plan to build 50 lakh dwelling units in five years across 400 towns and cities. The programme could free up thousands of acres of valuable government land across the country and generate crores worth of business for real estate developers. Proliferation of slums has had an adverse impact on the GDP growth for years. Slum dwellers are characterised by low productivity and susceptibility to poor health conditions. The government believes that better housing facilities will address social issues and also have a multiplier effect and serve as an economic stimulus.
- Development of land occupied by slums in cities of India will not have any effect on the common public.
- Majority of the slums in cities and towns in India are on prime private properties.
- Per capita income of slum dwellers is significantly lower than that of those living in better housing facilities.
- Cities and towns of developed countries are free from slums.
- Health and sanitary conditions in slums are far below the acceptable norms of human habitat in Indian cities and towns.
Before solving the sample problem, we must see the pattern of the problem and find out what it puts before the students to think.
A minute look will make you clear that here the examiner has graded the choices very closely. He/ she has given two positive choices instead of one.
- Definitely true
- Probably true
Further, he/ she has also given two negative choices instead of one:-
- Definitely false
- Probably false
This pattern requires a deeper thinking as it leaves before you following areas of confusion
- Definitely true or probably true
- Definitely false or probably false
- Data inadequate or probably true
- Data inadequate or probably false
Definitely true or probably true:
If the given inferences is a direct consequences of something given in the passage, then it falls under the category of definitely true. But the confusion may arise when the given inference is not directly stated in the passage but it appears ‘almost’ definitely true to you. But as it is not clearly stated in the passage, you may think that even ‘ Probably true ’ could be the answer. To get rid of this confusion, you have to recheck your reasoning. If the given inference has not been mentioned directly in the passage, then you must have assumed something ‘extra’ to draw this conclusion. Now, ask the following questions from yourself.
- Is the extra assumption an universal truth?
- Can the extra assumption never be false?
If you find ‘yes’ for the question (1) and ‘no never’ for the question (2), then accept it as definitely true, otherwise pick ‘Probably true’.
Definitely false or probably false
If the given inference does not follow from the passage, it falls under the category of definitely false. But confusion may arise when the given inference is not given directly in the passage and seems ‘almost’ definitely false. But as related things are not mentioned clearly in the passage, you think that ‘probably false’ maybe correct. To get rid of this confusion try to recheck your reasoning. If the opposite of the inference has not been mentioned in the passage, then you must assume something extra to reach your conclusion. Just ask the following questions to yourself.
- Is this assumption an universal truth?
- Can this assumption never be false?
If you find ‘yes’ for question (1) and ‘no, never’ for question (2) then select your answer as definitely false, otherwise probably false will be your correct answer.
Data inadequate or probably true
When an indirect inference is drawn from the passage, this confusion may arise. As the given inference is not explicitly mentioned, you think that data are inadequate and that sufficient information has not been given to draw a conclusion. However, the given inference appears to be in sync with the general ‘tone’ of the passage In such case you may go for ‘Probably true’.
To get rid of this confusion, recheck your general mental ability You can declare the given inference as probably true, if with the help of some extra assumption, the given inference seems likely to be true. Thus, you can some how convince yourself that the inference is likely to be true. On the other hand, you can declare that data are inadequate if no definite conclusion can be drawn from the passage even with the help of some extra assumption. Hence, in such case you can get convinced that the inference is likely to be true or false.
Data inadequate or probably false:
When the given inference is drawn indirectly from the passage, such confusion may arise. As it is not explicitly said in the passage, you come to the conclusion that data are inadequate because sufficient information has not been provided to draw a definite conclusion. However, the given inference appears to you in contradiction with the general ‘tone’ of the passage. Therefore, you are tempted to pick up ‘probably false’ as your answer. To get rid of this confusion recheck your general mental ability. You can declare an inference probably false. Only if you are able to find out a reasonable assumption, combining which with what is said in the given passage the inference appears likely to be false.
Thus, somehow, you can convince yourself that the given inference is likely to be false. On the other hand, you should pick up the choice ‘data are inadequate’ only if you can not find any acceptable assumption which, combined with what is said in the passage, may lead to some definite conclusion. In such case, you can not get convinced whether the given inference is likely to be true or false. Now, lets try to apply the above rules in the passage given above and try to solve the sample problems.
Solution to sample problems:
- As we have no information about how the freed up land will benefit the common public, hence data inadequate’ will be our correct answer choice. The passage do not suggest us any related assumption.
- The passage says to the contrary getting rid of slums would “Free up……valuable government land”. The inference does not follow from the passage.
- The extra assumption that makes this option probably true is : Low productivity is likely to lead to low income. The passage does not directly talk about per capita income.
- As slums have led to a lower GDP growth in India. The statement is in sync with the ‘tone’ of the passage. The extra assumption here can be that as countries develop they need to deploy things that improves their GDP. So it can be probably true that all slums vahish.
- The passage says that the slums dwellers are susceptible “to poor health conditions”. This is directly mentioned in the passage.