DU LLB Entrance Logical and Analytical Reasoning Syllabus

In syllogisms, what is the rule about conclusions drawn from two particular ('Some') premises?

No definite conclusion can be drawn from two particular premises. At least one premise must be universal to yield a valid definite conclusion.

In syllogisms, what is the rule about two negative premises?

No valid conclusion follows from two negative premises. At least one premise must be affirmative for a definite conclusion.

What is the 'possibility' rule in syllogism conclusions?

A possibility conclusion is valid if it does not contradict the definite information; when a definite relation isn't forced, the opposite case is at least possible.

What is a linear seating arrangement, and what key fact must you fix first?

People seated in a single row. First fix the direction they face (same way or facing each other), because left/right reverses depending on facing direction.

In a circular seating arrangement where all face the centre, how do 'left' and 'right' work?

When facing the centre, a person's left is the clockwise direction's neighbor's side... specifically: facing centre, right hand points clockwise? No—facing centre, the LEFT is clockwise and RIGHT is anticlockwise. Always anchor to one person to verify.

In circular arrangement, what changes if people face OUTWARD instead of toward the centre?

Left and right are reversed compared to facing inward. For outward-facing, right side is clockwise and left side is anticlockwise.

What is the first systematic step in solving any seating/puzzle arrangement?

Separate clues into 'definite' (fixed positions) and 'conditional/floating' clues. Place definite clues first, then use conditional ones to fill gaps.

In floor-based puzzles, what does 'an even number of floors between X and Y' help you eliminate?

It restricts gaps to 2, 4, 6... floors apart, eliminating arrangements with odd gaps and quickly narrowing possible positions for X and Y.

What is the purpose of drawing a grid/matrix in arrangement puzzles?

To map two or more variables (e.g., person vs. day vs. color) so you can mark confirmed (tick) and ruled-out (cross) combinations and avoid contradictions.

Define a Data Sufficiency question and its goal.

A question followed by two (or more) statements; you must decide whether the statements provide ENOUGH information to answer, not actually compute the final answer.

State the five standard answer options for a two-statement Data Sufficiency question.

(A) Statement I alone is sufficient; (B) Statement II alone is sufficient; (C) Both together are sufficient but neither alone; (D) Each alone is sufficient; (E) Both together are still insufficient.

What is the most common trap in Data Sufficiency questions?

Actually solving for the value instead of just checking sufficiency. You only need to know whether a unique answer is determinable, not the answer itself.

In Data Sufficiency, why must you evaluate each statement independently before combining?

To avoid 'carry-over' bias—information from Statement I must not be assumed while judging Statement II alone, or you'll wrongly mark a statement sufficient.

Define an Input-Output (machine) reasoning problem.

A 'machine' rearranges a line of words/numbers in steps following a hidden rule; you must identify the rule and predict a given step or the final output.

In Input-Output problems, how do you discover the operating rule?

Compare consecutive steps to see what moves each step—often the largest/smallest number or alphabetically first/last word is shifted to one end per step.

In an Input-Output 'shifting' type, if one element moves per step, how many steps to fully arrange n elements?

Typically n-1 steps (the last element falls into place automatically once the others are arranged).

What is the difference between 'strengthening' and 'weakening' an argument?

Strengthening adds support that makes the conclusion more likely true; weakening introduces information that makes the conclusion less likely or attacks the link between premise and conclusion.

What is the most effective way to weaken an argument that relies on an assumption?

Attack the underlying assumption—show the unstated link between evidence and conclusion is false, which collapses the argument's logic.

In strengthen/weaken questions, why are 'out-of-scope' options usually wrong?

They introduce facts irrelevant to the specific conclusion. Only information bearing directly on the argument's premise-to-conclusion link affects its strength.

Define an 'assumption' in critical reasoning.

An unstated premise that the argument takes for granted and needs to be true for the conclusion to hold. It bridges the stated evidence and the conclusion.

What is the 'Negation Test' for identifying a necessary assumption?

Negate the candidate assumption; if the argument falls apart (conclusion no longer follows), it IS a necessary assumption. If the argument survives, it is not.

What is the difference between an 'inference' and an 'assumption'?

An inference is a conclusion that logically FOLLOWS FROM the stated facts. An assumption is something taken for granted and used to REACH the conclusion (precedes it).

What rule governs a valid 'inference' in inference-type questions?

An inference must be something that must be true given the passage—it cannot go beyond, exaggerate, or add information not supported by the stated text.

In 'Course of Action' questions, when should a suggested action be regarded as a valid follow-up?

When it directly addresses the problem in the statement, is practical/feasible, and improves the situation. Reject actions that are extreme, impractical, or off-point.

In 'Course of Action', why is an action that merely restates the problem rejected?

A valid course of action must SOLVE or improve the situation; merely restating or describing the problem takes no corrective step, so it is not a proper action.

In Cause-and-Effect questions, how do you decide which of two events is the cause?

The earlier event that independently triggers the other is the cause; the dependent event that results is the effect. Check temporal order and the direction of dependence.

In Cause-Effect reasoning, what does it mean if two events are 'effects of a common cause'?

Neither event causes the other; both result from a third independent factor. Correlation here is not direct causation between the two given events.

In 'Statement and Argument' questions, what makes an argument 'strong'?

A strong argument is directly related to the issue, rational, and addresses a real practical aspect of it. Weak arguments are trivial, irrelevant, ambiguous, or based on simplistic assumptions.

In Statement-Argument evaluation, why are arguments framed as questions or with extreme/emotive wording usually weak?

They lack reasoned justification—rhetorical questions and exaggerated/emotional claims do not provide logical support directly tied to the statement, so they are deemed weak.

What is a Figure (Non-verbal) Series and how do you solve it?

A sequence of figures changing by a rule; identify how elements rotate, increase/decrease in number, change shape, or shift position per step, then pick the next figure following that rule.

In a Figure Analogy, what transformations should you check between the first figure pair?

Rotation (clockwise/anticlockwise and angle), reflection, change in number/size of elements, and addition/deletion of lines or shapes—then apply the same change to the second pair.

What is the rule for forming a MIRROR image of a figure or text?

Lateral inversion: left and right are reversed while top and bottom stay the same. For a vertical mirror, the image is flipped horizontally as if seen in a mirror placed beside it.

Which capital letters look the SAME in their mirror image (vertical mirror)?

Letters symmetric about the vertical axis: A, H, I, M, O, T, U, V, W, X, Y. They remain unchanged in a side mirror.

What is the rule for forming a WATER image of a figure or text?

Vertical inversion: top and bottom are reversed (upside-down reflection) while left and right stay the same, as if reflected in water below the object.

Which capital letters look the SAME in their water image (horizontal mirror)?

Letters symmetric about the horizontal axis: B, C, D, E, H, I, K, O, X. They appear unchanged when reflected in water.

What is an 'Embedded Figure' problem?

You must find which complex figure CONTAINS a given simple figure hidden within it, in the same orientation and proportion, without rotation or distortion.

What is the key constraint when locating a hidden/embedded figure inside a larger figure?

The target shape must appear in the same size and orientation (not rotated or flipped) and be a continuous part of the larger figure's line work.

In number-classification, why is 49 the odd one out among 23, 37, 49, 53?

23, 37, and 53 are prime numbers, but 49 = 7 x 7 is composite. The common property is 'prime', so 49 is the exception.

What is the quick method to count completed/embedded squares or triangles in a hidden-figure counting question?

Count systematically by size category: first the smallest unit shapes, then shapes made of 2 units, 4 units, etc., and sum them—this avoids missing or double-counting overlapping figures.

In coding-decoding, what is a 'symbol/condition-based' coding question?

Codes are assigned via given conditions (e.g., 'if first element is a vowel, swap first and last codes'). You apply the listed rules in order to encode/decode each item.