Advanced Reasoning — Puzzles, Seating, and Syllogisms

This chapter extends the reasoning foundations of Chapter 2 with a focused set of higher-difficulty puzzle, seating-arrangement, and syllogism questions of the kind increasingly seen in recent Delhi Police Constable papers.

Practice Set (12 MCQs)

1. Six friends P, Q, R, S, T, U sit around a circular table facing the centre. P sits second to the right of Q. R sits immediately left of P. S sits opposite Q. T sits immediately right of S. Where does U sit relative to Q?
   (a) Immediately left of Q (b) Immediately right of Q (c) Opposite Q (d) Two seats left of Q
2. In a family, A is B's father. C is B's sister. D is C's husband. How is D related to A?
   (a) Son-in-law (b) Son (c) Brother-in-law (d) Nephew
3. Five boxes of different weights are placed in ascending order. Box M is heavier than box N but lighter than box O. Box P is the lightest. Box Q is heavier than O. What is the correct ascending order?
   (a) P, N, M, O, Q (b) P, M, N, O, Q (c) N, P, M, O, Q (d) P, N, O, M, Q
4. Statements: All constables are disciplined. Some disciplined people are officers. Conclusion: Some constables are officers. Does this conclusion necessarily follow?
   (a) No, it does not necessarily follow (b) Yes, it follows validly (c) Only if all disciplined people are officers (d) Only if no officers are disciplined
5. In a row of eight students facing north, Aman sits third from the left. Bhavna sits immediately to his right. Two students sit between Bhavna and Chetan, with Chetan to Bhavna's right. What is Chetan's position from the left?
   (a) 7th (b) 8th (c) 6th (d) 5th
6. A is twice as old as B. Five years ago, A was three times as old as B. Find B's present age.
   (a) 10 years (b) 12 years (c) 8 years (d) 15 years
7. Statements: All patrol vehicles are equipped with GPS. No GPS-equipped vehicle is untracked. Conclusion: No patrol vehicle is untracked. Does this follow?
   (a) Yes, it follows validly (b) No (c) Cannot be determined (d) Only partially
8. In a code, DELHI is written as EFMIJ (each letter shifted one place forward). How is MUMBAI written using the same rule?
   (a) NVNCBJ (b) NVNCBI (c) MVNCBJ (d) NVMCBJ
9. Four friends W, X, Y, Z are standing in a queue. W is not at either end. X is immediately behind W. Y is at the front of the queue. Z is immediately behind X. What is the order of the queue from front to back?
   (a) Y, W, X, Z (b) Y, X, W, Z (c) W, Y, X, Z (d) Y, W, Z, X
10. Find the missing number in the series: 3, 7, 15, 31, ?
    (a) 63 (b) 62 (c) 64 (d) 60
11. In a group of seven officers seated in a row, Officer K is exactly in the middle. Officer L sits three places to the left of K. Officer M sits immediately to the right of K. How many officers sit to the right of M?
    (a) 2 (b) 3 (c) 1 (d) 4
12. Statements: No traffic signal is manually operated. Some manually operated devices are barriers. Conclusion: Some barriers are not traffic signals. Does this conclusion necessarily follow?
    (a) Yes, it follows validly (b) No, it does not follow (c) Cannot be determined (d) Only if all barriers are manually operated

Answer Key with Explanations

1.(a) P sits second to the right of Q; R sits immediately left of P; S sits opposite Q with T immediately right of S; working around the six seats, U is the one remaining seat, which falls immediately to the left of Q.

2.(a) C is B's sister, so C is also A's daughter; D is C's husband, and a daughter's husband is a son-in-law, so D is A's son-in-law.

3.(a) From the clues, P is lightest, N is next, then M, then O, then Q heaviest, giving the order P, N, M, O, Q.

4.(a) No, this does not necessarily follow: the "some disciplined people" who are officers may or may not include the specific people who are constables.

5.(a) Aman is third from the left (position 3); Bhavna is immediately right of Aman (position 4); with two students between Bhavna and Chetan, Chetan sits at position 4+2+1=7.

6.(a) Let B's present age be x and A's be 2x; five years ago, 2x−5 = 3(x−5), giving 2x−5 = 3x−15, so x=10.

7.(a) Yes, this follows validly: all patrol vehicles are equipped with GPS, and no GPS-equipped vehicle is untracked, so no patrol vehicle is untracked.

8.(a) Each letter shifts one place forward: M+1=N, U+1=V, M+1=N, B+1=C, A+1=B, I+1=J, giving NVNCBJ.

9.(a) Y is at the front; W is not at either end and X is immediately behind W, with Z immediately behind X, so the order is Y, W, X, Z.

10.(a) Each term follows ×2+1: 3×2+1=7, 7×2+1=15, 15×2+1=31, 31×2+1=63.

11.(a) With seven officers in a row and K in the exact middle (position 4), M is immediately to K's right (position 5), leaving positions 6 and 7 to M's right, so 2 officers sit to the right of M.

12.(a) Yes, this follows validly: no traffic signal is manually operated, and some manually operated devices are barriers, so those barriers (being manually operated) cannot be traffic signals, meaning some barriers are not traffic signals.