General Aptitude and Reasoning: Quant Shortcuts and Logical Structures
The aptitude section is scored per question like any technical item, so accuracy under time pressure matters. It spans arithmetic, data interpretation, verbal and non-verbal reasoning.
Quantitative aptitude
High-yield areas: percentages, ratio and proportion, time-speed-distance, time and work, profit and loss, simple and compound interest, averages and mixtures, permutations and probability, and mensuration. Most items yield to one clean relationship rather than long calculation.
Reasoning
Expect number and letter series, coding-decoding, blood relations, direction sense, syllogism, seating arrangement, clocks, calendars and figure series. In syllogism, draw the minimum possible Venn diagram - a conclusion is valid only if it holds in every diagram consistent with the premises.
Worked example
A 150 m train crosses a 300 m bridge in 30 s. Total distance = 450 m, so speed = 450/30 = 15 m/s = 15 × 18/5 = 54 km/h. Time to pass a signal pole = train length/speed = 150/15 = 10 s.
A syllogism check: "All relays are devices; some devices are digital." No conclusion linking relays and digital devices is valid, because the digital devices may lie wholly outside the relay set.
Traps
Skipping the km/h ↔ m/s conversion, treating "some A are B" as implying "some A are not B", using outside knowledge in verbal reasoning items, and over-reading data-interpretation charts by ignoring the axis scale or units.