College of Admission Tests Multan

Ordering

Solve the question of and select the option from the choices A through D/E. Check your Answer and view the explanation.

There are five people - Bushra, Nasir, Dani, Chohan, and Gori - in a police line-up standing in spaces numbered 1 through 6, from left to right. The following conditions apply:

There is always one empty space.

Chohan is not standing in space 1, 3, or 5.

Gori is the third person from the left.

Bushra is standing to the immediate left of Nasir.

Question: 3

If space 6 is empty, which one of the following must be false?
  • Chohan stands in space 4.
  • Dani stands in space 4.
  • Chohan is to the left of Nasir.
  • Chohan is to the right of Dani.
  • Nasir stands in space 2.

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Correct Answer: B

Our diagram will consist of six dashed lines, numbered 1 through 6 from left to right. Summarizing this information gives the following schematic:

1 ordering -20295900

Now, we decide the most effective order for placing the elements on the diagram. Following the guidelines on page 31, we look for a condition that fixes the position of an element. There is none. Next, we look for a condition that limits the position of an element. The second condition, “Gori is the third person from the left,” limits Gori to spaces 3 and 4. This condition, as often happens with ordering games, generates two diagrams: one with the empty space to Gori's left and one with the empty space to his right:

2 ordering -46656308

Next, we look for a condition that connects two or more people. The last condition, BN, connects B with N. However, at this stage we cannot place it on the diagram. Finally, we look for a condition that states where a person cannot be standing. The first condition states that Chohan cannot be standing in space 1, 3, or 5. Noting this on the diagram yields

3 ordering -40266604

(Note: D is “wild” because the conditions do not refer to him. Thus D can stand in more positions than any other person.) This diagram is self-contained. There is no need to refer to the original problem. If possible, always avoid rereading the problem. No further conditions can be derived, so we turn to the questions.

The structure of this question is awkward—the correct answer will always make a false statement! The question is more tractable when rephrased as “All of the following could be true EXCEPT.” Now, merely test each answer-choice against the initial conditions until you find the choice that violates one or more conditions. Adding the supplementary condition, “space 6 is empty,” to the original diagrams gives

41 ordering -32432402

In Diagram I, the only space open for C is space 2:

42 ordering -35953064

Clearly, this diagram does not leave room for the condition BN. So we eliminate Diagram I. Next, test each answer-choice against Diagram II, starting with (A). Place Chohan in space 4 as follows:

43 ordering -42847712

Now the condition BN forces B and N into spaces 1 and 2, respectively, which in turn forces D into space 5. So our uniquely determined diagram is

44 ordering -96273816

This diagram does not violate any initial condition. Hence Chohan could stand in space 4. So eliminate choice (A). Next, turning to choice (B), place Dani in space 4:

45 ordering -40297800

The condition BN forces B and N into spaces 1 and 2, respectively:

46 ordering -16599883

But this diagram forces C into space 5, violating the condition C ≠ 1, 3, 5. Hence D cannot stand in space 4, and the answer is (B).