GATE CS 2017 Set 2 Q.58 (GA Q.3): Analytical and Logical Reasoning

There are five buildings called V, W, X, Y and Z in a row (not necessarily in that order). V is to the West of W. Z is to the East of X and the West of V. W is to the West of Y. Which is the building in the middle?

Official answer and solution

Official answer: A
From: Official GATE 2017 answer key

Solution

Translate each relative directional constraint into a linear ordering along the West-East axis.

Let us represent the West-to-East row order from left to right:

'V is to the West of W': $V < W$ .
'Z is to the East of X and the West of V': $X < Z < V$ .
'W is to the West of Y': $W < Y$ .

Combine all three ordering relationships:

X < Z < V < W < Y

From West to East, the sequence of the five buildings is:

[\text{West}] \; X, \; Z, \; V, \; W, \; Y \; [\text{East}]

The building situated exactly in the middle (the 3rd of 5) is $V$ .
This corresponds to option A.

Final answer

Common trap

Assuming 'to the West of' implies immediately adjacent; while not strictly required, the relative order is uniquely determined here.

The answer is the one in the official GATE answer key. The solution is this site's own explanation.

Source

Paper: GATE 2017 Computer Science and Information Technology (CS) Session 2
Question: 58 of 65, printed as GA Q.3
Section: General Aptitude

Report an error in this question

GATE questions are the work of the organising institutes. This site is independent and is not affiliated with them.

Question

Solution

Source