Logical Reasoning and Data Interpretation
Logical Reasoning and Data Interpretation
SRCC GBO's LRDI section tests structured thinking: can you hold a set of constraints, eliminate impossible cases, and read a chart without being misled by scale or units? Reasoning topics include seating and floor puzzles, scheduling, blood relations, direction sense, syllogisms, coding-decoding, series, inequalities, and data sufficiency. DI includes tables, bar and line graphs, pie charts, caselets, and mixed charts.
Core rules
- Puzzles: write every clue as a constraint; start with the most restrictive one; make a small grid and eliminate.
- Circular arrangements: note whether people face the centre or outside; left and right reverse when facing outside.
- Syllogisms: draw minimal Venn diagrams. 'All A are B' does not imply 'All B are A'; 'Some A are B' does not imply 'Some B are not A'.
- DI: read the title, units, and footnotes first; compute only what the question asks; compare ratios rather than raw values when totals differ.
Worked example
Pointing to a photograph, Ravi says, 'She is the daughter of my grandfather's only son.' How is the girl related to Ravi? My grandfather's only son = Ravi's father. The daughter of Ravi's father is Ravi's sister. The trap is to stop at 'grandfather's son' and answer 'aunt' or 'cousin'; the word only fixes the son as Ravi's father.
Traps that cost marks
- Ignoring the direction faced in seating puzzles.
- Assuming a conclusion in syllogisms that is only possible, not certain.
- Reading a pie chart's percentages as absolute values.
- Using the wrong base year or total in a DI table.
- Spending too long on one puzzle; leave it and return.