Applying logic in UPSC General Studies Prelims


No, the heading of the post is not incorrect. You may think that logic is to be used in paper 2 (informally CSAT) and not in general studies. However, we can and we must use logic in general studies prelims paper as well. Given the vastness of UPSC syllabus, it’s just not possible to cover everything. Nevertheless basics can be covered and then we can apply logic to answer what may seem a difficult/advanced question.

What I call logic here, is essentially a composition of three techniques –

1. Applying basic knowledge to solve advanced/difficult questions
2. Avoiding extremeties
3. Calculated guess and risk

Let’s try to understand these by taking examples from actual UPSC paper.

 

1. Applying basic knowledge to solve advanced/difficult questions

 

When you come across a question that may seem difficult or is from a topic/area that you have not covered, NEVER EVER think that you won’t be able to answer it. Most people, however do exactly this. If they had left any topic and a question comes up from that , they already have formed an opinion that they won’t be able to answer it and in most cases skip the question without reading/trying it.

For e.g consider that you have not read in detail about animals found in India. This question then comes up. It’s from UPSC prelims 2012

Consider the following:
1. Black necked crane
2. Cheetah
3. Flying squirrel
4. Snow leopard
Which of the above are naturally found in India?
a) 1, 2 and 3 only
b) 1, 3 and 4 only
c) 2 and 4 only
d) 1, 2, 3 and 4

Now, you haven’t even heard of animals like black necked crane or flying squirrel. So, you thought you don’t have enough knowledge about these and it will be better to skip it. But read the options properly. Now, cheetah is not found naturally in India and this fact is something which you might be knowing even if you have not read animals in detail. So, if you just eliminate cheetah, statement 2 that is – you get only one option remaining and that has to be the answer.

Actually, UPSC just wanted to test your basic knowledge that whether you know about cheetah being not found naturally in India or not. It just made the questionm a bit complex to scare you. So, the advanced and difficult looking question was infact just a basic and easy one.

Another one, again from UPSC prelism 2012

Lead, ingested or inhaled, is a health hazard. After the addition of lead to petrol has been banned, what still are the sources of lead poisoning?
1. Smelting units
2. Pens and pencils
3. Paints
4. Hair oils and cosmetics
select the correct answer using the codes given below:
a) 1, 2 and 3 only
b) 1 and 3 only
c) 2 and 4 only
d) 1, 2, 3 and 4

Now you are no chemistry expert and have no idea where all lead is used and therefore decides to skip the question. But wait, UPSC is not looking for a chemical expert either. The question itself states that lead has been banned from use in petrol as it’s toxic. So now just think if that is the case, will lead be allowed to be used in pens and pencils which are used by children and most of them put it in their mouth? So, eliminate statement 2 about pens and pencils and there you get your answer.

Okay, another example again from chemistry. This is from UPSC prelims 2013

Due to improper/indiscriminate disposal of old and used computers or their parts, which of the following are released into the environment as e-waste?
1. Beryllium
2. Cadmium
3. Chromium
4. Heptachlor
5. Mercury
6. Lead
7. Plutonium
Select the correct answer using codes given below.
a) 1, 3, 4, 6 and 7 only
b) 1, 2, 3, 5 and 6 only
c) 2, 4, 5 and 7 only
d) 1, 2, 3, 4, 5, 6 and 7

OMG. Such a long question with so many elements, better leave this. But again, just apply some common knowledge. Plutonium is a radioactive element used for nuclear purposes. Will that be used in computers? No, never and there you get your answer by eliminating plutonium

The technique here again is eliminating options on the basic knowledge we have.

 
Let’s take another example from UPSC prelims 2012

If there were no phenomenon of capillarity
1. it would be difficult to use a kerosene lamp
2. one would not be able to use a straw to consume a soft drink
3. the blotting paper would paper would fail to function
4. the big trees that we see around would not have grown on the earth
Which of the following statements given above are correct?
a) 1, 2 and 3 only
b) 1, 3 and 4 only
c) 2 and 4 only
d) 1, 2, 3 and 4

Read statement 2 again. Now, even if capillarity was non-existent, we could still use a straw to drink isn’t it. So, statement 2 has to be incorrect, and that also helps us give our answer.

Remember, most of time if a question is complex, UPSC itself will give you enough hints to get to the answer. The point is are you smart enough to deduce that hint.

 

 

2. Avoiding extremities

 

UPSC seeks a candidate with balanced thought, right? Many times, UPSC gives such extreme statements in it’s question which cannot be true. You need to find this out which can immensely help you in answering the question. Statements with all, only, completelt etc are in most cases incorrect. I am saying most cases and not always.

Let’s try to understand this through examples. This is from UPSC 2011 prelims

At present , scientists can determine the arrangement or relative positions of genes or DNA sequences on a chromosome. How does this knowledge benefit us ?
1. It is possible to know the pedigree of livestock.
2. It is possible to understand the causes of all human diseases.
3. It is possible to develop disease-resistant animal breeds.
Which of the statements give above is/are correct ?
a) 1 and 2 only
b) 2 only
c) 1 and 3 only
d) 1,2, and 3

Read statement 2 again – It is possible to understand the causes of all human diseases. ALL human dieseas. Is that possible. Does your rational mind allows you to say that this statement can be correct. It’s not possible, statement is incorrect, eliminate 2 and you get your answer.

So, you see again UPSC gave you enough hint for a complex question.

Okay, now a question on history from UPSC 2013 prelims

The Chinese traveller Yuan Chwang (Hiuen Tsang) who visited India recorded the general conditions and culture of India at that time. In this context, which of the following statements is/are correct?
1. The roads and river-routes were completely immune from robbery.
2. As regards punishment for offences, ordeals by fire, water and poison were the instruments for determining the innocence or guilt of a person.
3. The tradesmen had to pay duties at ferries and barrier stations.
Select the correct answer using the codes given below.
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

So, you left ancient history as it was too much to cover and UPSC asked you some in depth question from it. You thought of skipping it. But for a moment just read statement 1 – The roads and river-routes were completely immune from robbery. COMPLETELY IMMUNE ? Again is that possible? As an UPSC aspirant you need to avoid extrmities, so things like completely, fully, all does not hold good for you. Even the most peaceful countries of Europe does not have anything like completely immune from crime places. So this is incorrect, eliminate statement 1 and get your answer.

 

3. Calculated guess

 

This is just a further step of technique 1 and 2. Many time you won’t be able to eliminate 3 options, but only 2. You may then need to put a calculated guess.

For instance, consider this from UPSC 2012 prelims

What are the reasons for the people’s resistance to the introduction of BT brinjal in India?
1. BT brinjal has been created by inserting a gene from a soil fungus into its genome.
2. the seeds of BT brinjal are terminator seeds and therefore, the farmers have to buy the
seeds before every season from the seed companies.
3. there is an apprehension that the consumption of BT brinjal may have adverse impact on health.
4. there is some concern that the introduction of BT brinjal may have adverse effect on the biodiversity.
Select the correct answer using the codes given below:
a) 1, 2 and 3 only
b) 2 and 3 only
c) 3 and 4 only
d) 1,2,3 and 4

BT is related with bacteria and must be known to you. So you can eliminate statement 1. But still you have two options left. C has more chances of being correct as you might have read about GM crops causing loss to biodiversity. So, as you can see, you did not get exact answer, but you came closer. You now only had two options, and can go on to take a calculated guess.

Let’s take another example. This is from UPSC 2013 prelims.

With reference to the usefulness of the by-products of sugar industry, which of the following statements is / are correct?
1.Bagasse can be used as biomass fuel for the generation of energy.
2. Molasses can be used as one of the feedstocks for the production of synthetic chemical fertilizers.
3. Molasses can be used for the production of ethanol.
Select the correct answer using the codes given below.
a) 1 only
b) 2 and 3 only
c) 1 and 3 only
d) 1, 2 and 3

Now you may not have much information about these, but you can sense that it’s related to biofuels and organic products. So, from where would synthetic fertilizer crop up here in statement 2. Therefore, statement 2 is false that is certain. This eliminates two options. You can then take a guess and your knowledge will tell you to guess for c) 1 and 3 which is the correct answer.

Another one

With reference to ‘stem cells’, frequently in the news which of the following statements is/are correct?
1. Stem cells can be derived from mammals only.
2. Stem cells can be used for screening new drugs.
3. Stem cells can be used for medical therapies.
Select the correct answer using the codes given below:
a) 1 and 2
b) 2 and 3 only
c) 3 only
d) 1, 2 and 3

Again following the technique of avoiding extremities, you can eliminate statement 1- Stem cells can be derived from mammals only. Still you have two options left and can put up a guess. Most people will mark b and that is the correct answer.

 

Now, after knowing all these techniques, can you answer the following question from our GS Prelims Mock Test Series 2015

Moderator is used in which of the following type of nuclear reactor?
1. Pressurized water reactor
2. Fast breeder reactor
3. Boiling water reactor
4. Heavy water reactor
Select the correct answer using the codes given below.
a) 1, 2 and 3 only
b) 1 ,3 and 4 only
c) 2 ,3 and 4 only
d) 1 ,2, and 4 only

All you needed to know was that fast breeder reactors are called fast because they do not used slowed down neutrons. So no moderator there. Even if you had no knowledge about other types of reactor, you can still answer this by using the techniques described above

 

Caution 

 

However, you need to be careful and please do not depend overtly and exclusively on these techniques. This is to be used only as a supplement and not as the main tool to answer questions. Read more, broaden your knowledge base, develop conceptual clarity as much as you can. These techniques will then become more and more useful.

The main point of this post was to give you hope that even though the syllabus seems huge, you can cover it by just covering the basic aspects, developing conceptual clarity and then using few techniques like these.

 

However, as I said, beware of it’s drawbacks and do not over use it. Your first choice for answering the questions should be knowledge and not these techniques. Take this question from our GS Prelims Mock test Series 2015 and see how this technique fails totally –

With reference to stem cells, consider the following statements:
1. Stem cells are found only in multi-cellular organism.
2. Placenta is a rich source of stem cell.
Which of the statements given above is/are correct?
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2

You may eliminate statement 1 because of the word only and since you may be avoiding extremities, but the fact is that statement 1 is correct.

 

As I always say, there are no shortcuts. You need to work regularly and work hard enough. However, things are not as difficult as it may seem. Syllabus is not as huge as it may appear. Questions are not as tough as they may seem at first reading. Just combine your hard work of gathering knowledge with some smart techniques given above, and you will easily sail through prelims. 

 

Self Study IAS’s 1000 Prelims MCQs with answer & detailed explanation @ Rs 350. Click here for more information.

Please read these important articles about prelims preparation

1. How UPSC asks current affairs in GS Prelims

2. How to practice prelims MCQs for UPSC

3. Applying logic in UPSC General Studies Prelims

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