IBPS PO (Probationary Officer) Reasoning Ability Syllabus

In Syllogism, what does an 'Either-Or' (complementary pair) case look like and when does it apply?

Either-Or applies when neither conclusion is individually definite, but the two conclusions are complementary - they cover all possibilities between the same two terms (typically a 'Some' and a 'No', or 'All' and 'Some-not' on the same pair). Then 'Either I or II follows' is the answer.

In Coded Inequality, what is the standard meaning of the symbols when 'A @ B' means A is not smaller than B, and 'A # B' means A is not greater than B?

'A is not smaller than B' means A >= B (greater than or equal). 'A is not greater than B' means A <= B (less than or equal). 'Not smaller' = greater-or-equal; 'not greater' = less-or-equal.

In Inequality, from A > B > C, what definite conclusion can be drawn about A and C, and what about B and any value equal to C?

Definite: A > C (the chain of strict greater-than is transitive). B is strictly greater than C, so B and C can never be equal.

In Inequality, why is no definite conclusion possible between A and C when the statement is A > B < C?

Because the inequality changes direction at B (A is greater than B, but C is also greater than B). A and C are not directly comparable - A could be greater than, less than, or equal to C. The relationship is indeterminate.

In Inequality, what combined relation results from A >= B and B > C, regarding A and C?

A > C (definite strict greater-than). Combining 'greater-or-equal' with 'strictly greater' gives strictly greater, because A is at least B and B is strictly above C.

What is 'Statement and Assumption' reasoning, and how do you define an assumption?

An assumption is something taken for granted - an unstated idea that the speaker/writer must believe to be true for the statement to make sense. A valid assumption is implicit (hidden) in the statement, not something already openly stated in it.

In 'Statement and Course of Action', when is a suggested course of action considered to 'follow'?

A course of action follows when it is a practical, logical and appropriate step that directly addresses the problem in the statement and is likely to improve or solve it - not when it is impractical, extreme, or merely restates the problem.

In 'Statement and Conclusion' questions, what is the golden rule about using outside knowledge?

You must draw conclusions ONLY from the information given in the statement, treating it as true. Do not use your own external/real-world knowledge; a conclusion follows only if it is logically and directly implied by the statement itself.

In Statement-Argument questions, what distinguishes a 'strong' argument from a 'weak' one?

A strong argument is directly related to the question, important, and based on facts or logical reasoning. A weak argument is unrelated, trivial, based on personal opinion/assumption, ambiguous, or restates the question without adding reasoning.

In Critical Reasoning, what is the difference between an 'inference' and an 'assumption'?

An inference is a conclusion that can be logically drawn FROM the given statements (it follows after). An assumption is an unstated premise that the argument depends on and is taken for granted BEFORE the conclusion. Inference comes out of the passage; assumption is built into it.

In Critical Reasoning, what does it mean for an option to 'strengthen' versus 'weaken' an argument?

A strengthening statement provides additional support that makes the conclusion more likely to be true. A weakening statement introduces a fact or alternative that makes the conclusion less likely or attacks the link between the premises and the conclusion.

In Critical Reasoning, what is a 'cause and effect' question and what should you watch out for?

It presents two events and asks how they are related (one causes the other, both have a common cause, both are independent, etc.). Watch out for assuming causation from mere correlation - co-occurrence alone does not prove one event caused the other.

What is Coding-Decoding, and name three common types of coding patterns asked.

Coding-Decoding tests deciphering a rule by which words/numbers are encoded. Common types: (1) Letter coding (shifting letters by fixed positions), (2) Number/Substitution coding (letters replaced by numbers), and (3) New-pattern (sentence/word-based) coding where each word maps to a code.

In letter-shift Coding-Decoding, if 'CAT' is coded as 'DBU', what is the rule and how is 'DOG' coded?

The rule is: shift each letter forward by +1 position (C to D, A to B, T to U). Applying +1 to DOG: D to E, O to P, G to H, giving 'EPH'.

In Coding-Decoding, what is 'new pattern / coded sentence' coding and how do you crack it?

Several sentences are given with codes; each word has a code but the order is scrambled. You crack it by comparing two sentences that share a common word - the common code among them stands for that common word. Repeat the comparison to map every word.

In number-based Coding-Decoding, what is meant by 'each letter coded by its position value' and what is the position value of letter J?

It means A=1, B=2, ... Z=26, where each letter is replaced by its serial position in the alphabet. The position value of J is 10.

What is a Machine Input-Output problem, and what stays constant across all steps?

It gives a machine that rearranges an input line of words/numbers in successive steps until a final output is reached. The shifting LOGIC (rule applied at each step) stays constant; only the arrangement changes. You must identify that rule from the given steps.

In Machine Input-Output, name three common arrangement logics a machine may use.

(1) Arrange words alphabetically or numbers in ascending/descending order (typically one element shifted per step from one end), (2) Shift the largest/smallest element to one end each step, and (3) Apply mathematical operations or interchange positions in a fixed pattern each step.

In Machine Input-Output, how do you find the input if only an intermediate step is given?

You generally CANNOT uniquely reconstruct the original input from an intermediate step, because the operation is not reversible (you don't know what was already arranged before). Questions therefore ask only about forward steps or the final output, not backward to the input.

What is an Alphanumeric Series, and what types of elements does it typically mix?

An Alphanumeric series is a sequence mixing letters, numbers and symbols. Questions ask about elements based on their position, neighbours (e.g. a number immediately preceded by a letter and followed by a symbol), or counting elements that meet a condition.

In an Alphabet Series, what is the position number of the letter that is 'as far from the beginning as R is from the end'?

R is the 18th letter, so from the end it is the 26 - 18 + 1 = 9th letter. The 9th letter from the beginning is I. (Use rank-from-other-end = 27 - rank.)

In number/letter series problems, how do you approach a series like 2, 6, 12, 20, 30, ? to find the next term?

Find the pattern of differences: 6-2=4, 12-6=6, 20-12=8, 30-20=10 (differences increase by 2). The next difference is 12, so the next term is 30 + 12 = 42. (Equivalently each term is n(n+1).)

In a Symbol Series of conditions, what does a coding condition like 'if a symbol is between two numbers, code it X' require you to check?

It requires you to examine the immediate left and right neighbours of each symbol; the rule applies only when BOTH the immediately preceding and immediately following elements are numbers. Position-based conditional rules must be checked element-by-element.

What is an Analogy question in reasoning, and what is the key to solving it?

An Analogy presents a pair with a specific relationship (A : B) and asks you to find a matching pair (C : D) with the SAME relationship. The key is to precisely identify the relationship in the first pair (e.g. cause-effect, part-whole, synonym, function) and apply the identical logic.

Give an example of a 'part-to-whole' analogy and contrast it with a 'function-based' analogy.

Part-to-whole: Petal : Flower (a petal is a part of a flower). Function-based: Knife : Cut (the function of a knife is to cut). The relationship type must match for the analogy to be valid.

What is Classification (Odd-One-Out), and what is the solving approach?

Classification gives several items of which all but one share a common property; you must find the odd one out. The approach is to discover the common rule/category linking the majority, then identify the single item that breaks that rule.

In Classification, why would 'Triangle, Square, Circle, Rectangle' have 'Circle' as the odd one out?

Triangle, Square and Rectangle are all closed figures made of straight sides (polygons) with corners; a Circle has no straight sides or vertices. So Circle is the odd one out.

What is Data Sufficiency in Reasoning, and what question does it really ask?

Data Sufficiency gives a question followed by two (or more) statements; you must decide whether the statements provide ENOUGH information to answer - not actually solve it. The task is to judge sufficiency, individually and in combination, not to find the final answer itself.

State the standard Data Sufficiency answer options (the five-option convention used in IBPS PO).

(a) Statement I alone is sufficient but II alone is not; (b) Statement II alone is sufficient but I alone is not; (c) Each statement alone is sufficient; (d) Both statements together are still NOT sufficient; (e) Both statements together are sufficient but neither alone is. (Exact labelling can vary, but these are the five cases.)

In Data Sufficiency, what is the most common mistake candidates make, and the correct mindset?

The common mistake is fully solving the problem and wasting time, or carrying assumptions from Statement I into Statement II. The correct mindset is to evaluate each statement INDEPENDENTLY for sufficiency first, then together only if needed, deciding only whether a unique answer is determinable.