CAT 2023 Slot 3 · DILR · Question 6

CAT 2023 Slot 3 previous year question on Caselet DI, with the answer and a step-by-step solution.

Caselet DIData InterpretationMultiple choiceMedium

Set 2: Police Teams Patrolling Six Stations — this question belongs to a set. Read the full set with all 5 questions →

A, B, C, D, E and F are the six police stations in an area, which are connected by streets as shown below. Four teams - Team 1, Team 2, Team 3 and Team 4 - patrol these streets continuously between 09:00 hrs. and 12:00 hrs. each day.

The teams need 30 minutes to cross a street connecting one police station to another. All four teams start from Station A at 09:00 hrs. and must return to Station A by 12:00 hrs. They can also pass via Station A at any point on their journeys.

The following facts are known.

1. None of the streets has more than one team traveling along it in any direction at any point in time.

2. Teams 2 and 3 are the only ones in stations E and D respectively at 10:00 hrs.

3. Teams 1 and 3 are the only ones in station E at 10:30 hrs.

4. Teams 1 and 4 are the only ones in stations B and E respectively at 11:30 hrs.

5. Team 1 and Team 4 are the only teams that patrol the street connecting stations A and E.

6. Team 4 never passes through Stations B, D or F.

Which one among the following stations is visited the largest number of times?

  1. A

    Station C

  2. B

    Station E

  3. C

    Station D

  4. D

    Station F

Pick an option, then check.
Answer & solution

Answer: Option B

Solving the set

Streets (from the map): A–B, A–C, A–E, A–F, E–F, E–D, C–D. Every 30 minutes each team moves to a neighbouring station, so each team visits a station at 9:30, 10:00, …, 11:30 and is back at A at 12:00 (6 moves).

Step 1 – Team 3 is at D at 10:00, two moves after leaving A, without using A–E (fact 5): its route starts A–C–D. Team 2 is at E at 10:00, two moves after leaving A, without A–E: the only such route is A–F–E.

Step 2 – Team 4 moves only among A, C and E (fact 6) and must use A–E (fact 5). It cannot be at E at 10:00 or 10:30 (facts 2, 3), and it is at E at 11:30. Starting A–C would put it on street A–C together with Team 3 between 9:00 and 9:30 (fact 1), so it starts A–E. Its route is A–E–A–C–A–E–A.

Step 3 – Team 1 at 9:30: streets A–C, A–F and A–E are taken in the first half hour (Teams 3, 2, 4), so Team 1 goes to B and returns to A at 10:00. It reaches E at 10:30 by A–E, and must be back at A at 11:00 to be at B at 11:30. Route: A–B–A–E–A–B–A.

Step 4 – Team 3 after E at 10:30: going to F would leave it unable to reach A at exactly 12:00 without passing E at 11:30 (reserved for Team 4), so it returns E–D–C–A. Route: A–C–D–E–D–C–A.

Step 5 – Team 2 after E at 10:00: E–D would clash with Team 3 on street D–E (10:00–10:30) and E is reserved at 10:30, so it goes to F. From F it goes to A or E at 11:00. At 11:30 it cannot be at E (Team 4 only) or B (Team 1 only); going A–C would make it share street C–A with Team 3 between 11:30 and 12:00. So it is at F at 11:30 and back at A at 12:00.

Team

9:00

9:30

10:00

10:30

11:00

11:30

12:00

Team 1

A

B

A

E

A

B

A

Team 2

A

F

E

F

A or E

F

A

Team 3

A

C

D

E

D

C

A

Team 4

A

E

A

C

A

E

A

Station

Visits (excluding start and finish at A)

Count

B

Team 1 at 9:30 and 11:30

2

C

Team 3 at 9:30 and 11:30, Team 4 at 10:30

3

D

Team 3 at 10:00 and 11:00

2

E

T1 10:30, T2 10:00 (and maybe 11:00), T3 10:30, T4 9:30 and 11:30

5 or 6

F

Team 2 at 9:30, 10:30 and 11:30

3

This question

From the visits table, Station E is visited 5 or 6 times, more than C (3), F (3) and D (2).

Hence, the answer is option 2.

More Caselet DI questions

All Caselet DI PYQs →

Take this paper as a timed test
Real exam timing, instant score, rank and topic-wise analysis.

Practice timed →