Seven people T, U, V, W, X, Y & Z are standing in a single line facing a milk - booth. X is somewhere ahead of Y. There is exactly one person standing between V and Z. W is immediately behind T. Y is behind both U & W. If W & V are fourth and fifth in line respectively, then which of the following must be true?

Y is sixth

The correct answer is Option (3) → Y is sixth

1. Fix the definite positions

We are explicitly told the positions of W and V:

• Position 4: W
• Position 5: V

2. Place T and Z based on immediate neighbors

• W is immediately behind T: Since W is 4th, T must be 3rd.
• Exactly one person between V and Z: V is 5th. This means Z must be 7th (Z cannot be 3rd because T is already there).

3. Place U, X, and Y

We have positions 1, 2, and 6 remaining.

• Y is behind both U and W: Since W is 4th, Y must be in a position later than 4. The only available spots behind 4 are 6 and 7. Since Z is already at 7, Y must be 6th.
• X is ahead of Y: X can be in position 1 or 2.
• U is ahead of Y: U can be in position 1 or 2.

Final Lineup:

Evaluation of Options:

• T is first: False (T is 3rd).
• Z is first: False (Z is 7th).
• Y is sixth: True.
• Y is seventh: False (Z is 7th).

Correct Answer: Y is sixth