NIELIT 2019 Feb Scientist D - Section A: 18

Question

Read the following information carefully and answer the questions given below :

1. Five students Sujit, Randhir, Neena, Mihir and Vinay have total five books on subjects Physics, Chemistry, Maths, Biology and English written by authors Gupta, Khanna, Harish, D'Souza and Edwin.Each student has only book on one of the five subjects.
2. Gupta is the author of Physics book, which is not owned by Vinay or Sujit.
3. Mihir owns the book written by Edwin.
4. Neena owns Maths book. Vinay has English book, which is not written by Khanna. Biology book is written by D'Souza.

Who is the author of Chemistry book?

• A. Harish only
• B. Edwin only
• C. Khanna or Harish
• D. Edwin or Khanna

Answer 1

Ans is option (B)

From the given data, I will fill information in two tables(namely Subject-Student-Author and Author-Subject).

→ Correct entries are marked in bold letters in each cell.

After analyzing the information, we get the tables as:

  Subject-Student-Author Table

Subject	Chemistry/Biology	Physics/Chemistry/ Biology	Maths	Physics/Chemistry/ Biology	English
Student	Sujit	Randhir	Neena	Mihir	Vinay
Author	Khanna/Harish/ Edwin/D’Souza	Gupta/Khanna/ Harish/Edwin/ D’Souza	Khanna/Harish/ Edwin	Edwin	Harish/Edwin

 

Author-Subject Table

Author	Gupta	Khanna	Harish	D’Souza	Edwin
Subject	Physics	Chemistry/Maths	English/Chemistry/Maths	Biology	English/Chemistry/Maths

 

It is given that the Physics book is not owned by neither Sujit nor Vinay. Also, since Neena has Maths book and Vinay has English book, we get two possibilities for Physics book owner i.e. Mihir and Randhir. Now, since Mihir owns a book written by Edwin(who is not the author of Physics book), we can safely say that  Randhir owns the Physics book, and hence Randhir’s book details will be  Physics-Randhir-Gupta..

Now, since Khanna is not the author of the English book, English as a subject can be placed as a possibility only in Harish and Edwin’s column in Author-Subject table. Now, in the Subject-student-author table, in the Vinay’s book details, we can only place Harish as Edwin is already present in Mihir’s book details. So, Vinay has English book written by Harish.

Now, in Neena’s book details, we have Khanna/Harish/Edwin, from which Harish and Edwin can be safely removed. So, Khanna is the author of Maths book.

Also, Edwin’s subject possiblities were English, Chemistry and Maths, from which English and Maths can be safely removed(their respective authors being Harish and Khanna). So, Edwin is the author of Chemistry book. Also, under Sujit’s book details, Khanna,Harish and Edwin can be safely removed now, which confirms the fact that D’Souza is the author of Biology book.

Now, summarizing all the results, we get the two final tables as:

Subject	Biology	Physics	Maths	Chemistry	English
Student	Sujit	Randhir	Neena	Mihir	Vinay
Author	D’Souza	Gupta	Khanna	Edwin	Harish

 

Author	Gupta	Khanna	Harish	D’Souza	Edwin
Subject	Physics	Maths	English	Biology	Chemistry

 

So,the chemitry book is written by Edwin only.