Reasoning: Pattern, Arrangement and Deduction Questions
The Reasoning section tests pattern recognition and deductive accuracy: series completion, coding-decoding, analogy, blood relations, direction sense, syllogism, seating and ranking puzzles, and non-verbal items such as figure series and mirror images.
Rules that decide most questions
- Never assume the converse of a statement. All A are B does not imply all B are A; some A are B does not imply some B are not A.
- In seating puzzles fix one anchor and place every clue relative to it. Left and right in circular arrangements depend on whether people face the centre or face outward.
- In direction questions sketch each leg and combine displacements; use Pythagoras when the final leg is not parallel to an earlier one.
- A mirror image reverses left and right but not top and bottom; a water image does the reverse.
- Clock problems: the minute hand gains 5.5 degrees per minute on the hour hand.
Worked example
An aircraft tracking east flies 3 km, then 4 km north, then 5 km west. Its position is 3 minus 5, that is 2 km west, and 4 km north of the start. Straight-line distance from the start is sqrt(2 squared plus 4 squared), that is sqrt(20), about 4.47 km. Had the third leg been omitted, the 3-4-5 triangle would have given exactly 5 km on a north-easterly bearing.
Traps
Accepting a syllogism conclusion that reverses the given relation; mixing left and right when people face outward in a circle; forgetting that a mirror image is not a rotation; solving a direction question without a sketch and losing the sign of a leg.