Logical Reasoning – UPSC CSAT

Syllogism questions give two or more statements, assumed true even if they sound odd, and ask which conclusions must follow. The safest method is to draw Venn diagrams and look for any arrangement that breaks…

Blood-relation questions describe a family through a chain of statements and ask how two people are related. Drawing a small family tree – with generations in rows and genders marked – prevents almost every mistake.…

Direction questions trace a person's walk through turns and distances. With a quick sketch on coordinates, both the final distance and the direction from the start become simple. North is up, east right, south down,…

Coding-decoding questions hide a rule that turns words into letters or numbers. Write the alphabet positions once, compare the sample word with its code letter by letter, and the rule usually shows itself within a…

Seating arrangements combine clues into one consistent picture. Rows and circular tables are most common. People in a row facing north: their right is east (your right on the page); facing south, their right is…

Ordering and scheduling puzzles ask you to rank people (by height, marks, age) or place them in time slots (days, floors, periods). They are seating arrangements in one dimension and reward a systematic grid. Turn…

Series questions ask for the next or missing term. Most CSAT series follow a handful of patterns; checking them in a fixed order solves nearly every question in under a minute. Constant difference (arithmetic): 7,…

Calendar questions ask for the day of the week for a date, or which year repeats a calendar. The idea of 'odd days' – days left over after complete weeks – makes them mechanical. An…

Clock questions involve the angle between the hands, times when the hands coincide or are at right angles, and clocks that gain or lose time. All follow from the relative speed of the two hands.

Cube and dice questions test spatial visualisation. Painted-cube questions have exact formulas, while dice questions are solved by noting which faces can be seen together. A large cube painted on all faces and cut into…

Venn-diagram questions count overlapping groups – people who like tea or coffee, students in several clubs. Inclusion–exclusion gives the answer, and filling the diagram from the centre outwards prevents double counting. n(A ∪ B) =…

Data sufficiency asks not for the answer itself but whether the given statements are enough to find a unique answer. It rewards disciplined thinking: test each statement alone, then together, and stop as soon as…

This family of critical-reasoning questions gives a short statement and two possible assumptions, conclusions or courses of action. The skill is to judge what is necessarily implied or practically sensible – using only the statement…