Five persons are standing in a queue, one of the two persons at the extreme ends is a doctor and the other is an engineer. An advocate is standing to the right of the student. An author is to the left of the engineer. The student is standing between the doctor and the advocate. If the advocate and engineer exchange their positions and also the author and the student, then who will be standing to the left of the author?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Engineer
Note: The given answer is as per the official NTA Answer Key. However, the answer given by NTA appears to be incorrect: after both exchanges the doctor stands to the left of the author and the engineer to the author’s right, so Option (1) is the correct answer, as explained below.
The queue from the clues (left to right):
The author is to the left of the engineer, so the engineer cannot be at the left end: the doctor is at the left end and the engineer at the right end.
The student is between the doctor and the advocate (next to both), with the advocate to the student’s right: Doctor, Student, Advocate. The author takes the one place left, fourth, to the engineer’s left: Doctor, Student, Advocate, Author, Engineer.
The two exchanges:
Advocate and engineer exchange: Doctor, Student, Engineer, Author, Advocate
Author and student exchange: Doctor, Author, Engineer, Student, Advocate
Option (1) Doctor — Should have been correct. The doctor stays at the left end and is the only person to the author’s left.
Option (2) Engineer — Correct as per NTA; however, the engineer stands to the author’s right. The engineer is left of the author only before the second exchange, when the author is still fourth.
Option (3) Advocate — Incorrect. The advocate ends at the right end of the queue.
Option (4) Student — Incorrect. After exchanging with the author, the student is fourth, to the author’s right.