In-Depth Tutorial
A formal, accessible 800–1000 word walkthrough of this topic, written for the serious aspirant. Switch to हिन्दी using the toggle on the right.
Why Logic-Based Reasoning Is the Most Predictable Score-Booster
Syllogism, statement-and-conclusion, statement-and-assumption, and inequality questions form the formal-logic family of reasoning. Unlike puzzles, which require minutes of construction, a logic question is rule-bound: once the candidate has internalised the rules of valid inference, every question in the family becomes a near-mechanical application. This predictability is precisely why these questions consistently appear in the Staff Selection Commission, the Institute of Banking Personnel Selection, the Reserve Bank of India recruitment, the State Public Service Commissions, and the preliminary papers of the Combined Defence Services and the Civil Services.
An aspirant who has spent ten focused hours on this family can typically solve a five-question syllogism set in three minutes and a five-question inequality set in two minutes — eight to ten near-certain marks per paper. There is no other topic in reasoning where the time-to-mark ratio is as favourable.
Syllogism — The Logic of All, Some and No
A syllogism question presents two or three statements such as 'All cats are mammals; All mammals are animals' and asks the candidate to determine which conclusions definitely follow. Four standard statement types exist: universal affirmative ('All A are B'), universal negative ('No A are B'), particular affirmative ('Some A are B') and particular negative ('Some A are not B'). The candidate must learn the eight valid combinations of two premises and the conclusions each combination yields.
The Venn-diagram method is the most reliable in the examination hall. The candidate draws a possibility diagram for each premise, then checks each conclusion against every possible diagram. A conclusion follows only if it is true in every possibility, not merely in one. This single discipline — testing across all possibilities — converts the trickiest syllogism into a mechanical task. The two famous extensions, 'either-or' and 'possibility' conclusions, are then specific cases of this general method.
Statement and Conclusion — Reading Without Adding
Statement-and-conclusion questions present a short paragraph and a list of conclusions, asking which conclusions definitely follow from the statement alone. The single most important rule is to never bring in outside knowledge. If the statement says, 'The government has reduced petrol prices,' the candidate cannot conclude that inflation will fall; that conclusion may be true in real life but is not stated. The conclusion must be derivable strictly from the words on the page.
The professional method is to underline the key claim of the statement, then read each conclusion and ask only one question: does the statement, taken at face value, force this conclusion? If even one alternative interpretation of the statement allows the conclusion to be false, the conclusion does not follow. This strictness is what distinguishes a candidate who scores three out of five from a candidate who scores five out of five.
Statement and Assumption — The Implicit Foundation
An assumption is a fact that must be true for the statement to make sense, even if it is not explicitly stated. For instance, the statement 'Please carry an umbrella when you leave the house' assumes that it may rain or that the sun may be intense. The candidate's task is to determine whether the listed assumption is implicit in the statement.
Two reliable tests are used. First, the negation test — if negating the assumption makes the statement collapse into nonsense, the assumption is implicit. Second, the necessity test — if the action recommended in the statement would still make sense without the assumption, the assumption is not implicit. Applying both tests in succession resolves almost every borderline case in this sub-topic, including the deliberately confusing examples that examiners include to separate average from excellent candidates.
Inequality — Symbol Translation Made Simple
Inequality questions present sequences of symbols such as A > B ≥ C < D and ask which conclusions hold. The professional method is a two-step translation. First, simplify the chain so that each pair of consecutive variables is connected by a single direction-aware relation. Second, evaluate each conclusion against the simplified chain.
Three rules govern conclusions. First, a strict inequality combined with another strict inequality of the same direction yields a strict inequality. Second, a strict inequality combined with a non-strict inequality (≥ or ≤) of the same direction yields a strict inequality. Third, two non-strict inequalities of the same direction yield a non-strict inequality. Mixing directions blocks any conclusion entirely. Coded inequality, where symbols such as @, # and $ replace the standard signs, is solved by writing a two-line key at the top of the rough sheet and treating the question as a routine inequality thereafter.
A Two-Week Mastery Plan
An efficient plan covers the entire logic family in two weeks. The first week treats syllogism and inequality, with twenty syllogism questions and twenty inequality questions per day, every question solved with a Venn diagram or a translated chain even when the answer feels obvious. This drill builds the habit of writing the diagram first and answering only afterwards.
The second week treats statement-conclusion and statement-assumption, with fifteen questions of each per day, focusing on the negation and necessity tests. By the end of the fortnight, the candidate is capable of solving any logic-family set in under five minutes with ninety-five-percent accuracy. These eight to ten reliable marks then form the high-confidence anchor that allows the candidate to spend more time on the harder puzzle sets in the same paper.