Dear Reader, Below are 2 logical reasoning questions where you will have to interpret the statements and check which of the conclusions definitely follow (i.e definitely true) based on the given statements. Sometimes these questions can become bit time consuming due to the nature of these questions where one generally has to draw venn diagrams to solve.
Question 1
Statements:
a. No speeches are lectures
b. All lectures are sermons
c. No sermons are advice.
Conclusions:
I. Some sermons are speeches
II. No sermons are speeches
III. No advices are lectures
IV. Some speeches are not advices.
Options :
a) All follow b) Only II, III and IV follow c) Only I, III and IV follow d) None of these
Answer : d) None of these.
Reason :
Combining Statement (a) + Statement (b) we can draw three possible diagrams for this combination.
Fig 1
Here L refers Lectures
Fig 2
Fig 3
In all the above diagrams one thing that is certain is that sermons which are lecturers can never be speeches. This means, some sermons are not speeches.Hence conclusions I and II do not follow.
Combining Statement (b) + Statement (c), we can represent via the below diagram.
Fig 4
From the above diagram we can certainly say that No advices are lecturers. Hence conclusion III follows.
Also no definite relation can be established between Speeches and Advices from the data given. Hence, conclusion IV does not follow.
Result : Only conclusion III follows. But this is not reflected in any of the options, hence d) None of these has to be the answer.
Question 2
Statements:
a. No mangoes are grapes
b. No grapes are apples
c. No apples are bananas.
Conclusions:
I. No mangoes are apples
II. No grapes are bananas.
III. No apples are mangoes
IV. No bananas are grapes.
Options :
a) All follow b) None follows c) Only I and III follow d) Only II and IV follow
Answer : b) None follows.
Reason :
For all the statements a,b and c combined, there are three possible diagrams as given below :
Fig 5
Fig 6
Fig 7
From the above diagrams, one cannot say definitely that No mangoes are apples. (Though fig VI conveys a possibility that No mangoes can be Apples, this is just one of the possibilities and not definite truth.)
The same type of arguments hold for conclusion II as well. Yes, there is no definite answer for relationship between grapes and bananas as well.
Conclusions III and IV are just rephrased versions of conclusions I and II respectively, hence need not be checked again.
Hence, we can safely say that the answer is b) None follows.
