Directions (77-81): Read the following information carefully and answer the questions given below:

Ten persons- M, N, O, P, Q, R, S, T, U and V live on different floors of a ten-storey building where ground floor is numbered as 1, above it is 2 and so on till the topmost floor is numbered as 10.

Four persons live between N and O who lives immediate below P. N lives on an even numbered floor but not on top floor. Q lives three floors below P. The number of persons live above R is same as the number of persons live below S but they do not live adjacent to each other. T lives adjacent to S. U lives on an odd numbered floor but above V and below M.

Which among the following is incorrect?

The correct answer is S – 2nd Floor. This statement is incorrect. Let's derive the exact floor arrangement step-by-step to prove it.

Step 1 – Placing N, O, and P together

The clue says: "Four persons live between N and O, and O lives immediately below P." This means N and O are exactly 5 floors apart (4 persons in between). Also, O and P are consecutive with P just above O.

N must be on an even-numbered floor but NOT the top floor (floor 10). Testing valid combinations where N is even:

If N = 4, O = 9, then P = 10. ✓ (N is even, not 10, and exactly 4 floors — 5, 6, 7, 8 — lie between floors 4 and 9.)

Step 2 – Placing Q

Q lives three floors below P. P = 10, so Q = 10 - 3 = 7.

Step 3 – Placing R and S

The clue says: "The number of persons above R equals the number of persons below S, and they do not live adjacent to each other."

If R is on floor r, persons above R = 10 - r.
If S is on floor s, persons below S = s - 1.
Setting them equal: 10 - r = s - 1 → r + s = 11.

Floors already taken: 4 (N), 7 (Q), 9 (O), 10 (P). Remaining floors: 1, 2, 3, 5, 6, 8.

Valid pairs from remaining floors where r + s = 11 and |r - s| ≠ 1 (not adjacent):
- R = 8, S = 3: |8 - 3| = 5 ✓ (not adjacent)

Step 4 – Placing T

T lives adjacent to S. S = 3, so T = 2 or T = 4. Floor 4 is taken by N, so T = 2.

Step 5 – Placing U, V, and M

Remaining floors after placing everyone so far: 1, 5, 6 for M, U, V.

The clue says: "U lives on an odd-numbered floor, above V, and below M."
Available odd floor from {1, 5, 6}: 1 and 5.
If U = 5: V must be below 5 → V = 1; M must be above 5 → M = 6. ✓
(U = 5 is odd ✓, U above V: 5 > 1 ✓, U below M: 5 < 6 ✓)

Final Floor Arrangement:

Floor 10 → P
Floor 9 → O
Floor 8 → R
Floor 7 → Q
Floor 6 → M
Floor 5 → U
Floor 4 → N
Floor 3 → S
Floor 2 → T
Floor 1 → V

Step 6 – Verifying all the given options:

- P – 10th Floor → P = 10 ✓ Correct
- Q – 7th Floor → Q = 7 ✓ Correct
- N – 4th Floor → N = 4 ✓ Correct
- S – 2nd Floor → S = 3, NOT the 2nd floor ✗ Incorrect!

Therefore, the statement "S – 2nd Floor" is the incorrect one. S actually resides on the 3rd floor, not the 2nd.