Logical Reasoning and Numerical Ability (Λογική Σκέψη και Αριθμητική Ικανότητα)
What is tested
Series completion, analogies, syllogisms, coding and ordering puzzles, plus arithmetic word problems: percentages, ratios, averages, speed, work rates, profit and loss, and simple table interpretation. Nothing requires advanced mathematics; everything requires disciplined reading.
Core methods
- Number series. Test first differences, then ratios, then alternating or second-order differences. Confirm a rule with at least two terms before using it.
- Syllogisms. Draw the minimal diagram. From 'some A are B' you may not conclude 'all B are A'; only a conclusion that must be true is valid.
- Percentages. Successive changes multiply (×0.85 then ×1.10), they never add. A 15% cut followed by a 10% rise is not a 5% cut.
- Ratios. Convert to parts of a whole before sharing out an amount.
- Speed. Convert km/h to m/s by dividing by 3.6; an out-and-back journey's average speed is the harmonic mean, not the arithmetic mean.
Worked example
Find the next term: 2, 6, 12, 20, 30, ? Step 1 - first differences: 4, 6, 8, 10. This is an arithmetic sequence increasing by 2, so the next difference is 12. Step 2 - apply: 30 + 12 = 42. Step 3 - cross-check with a second rule: n(n+1) gives 1×2=2, 2×3=6, 3×4=12, 4×5=20, 5×6=30, 6×7=42. Confirmed. The trap answer is usually 60, obtained by doubling the previous term - a rule that fits the first pair but not the rest.
Traps that cost marks
- Answering the wrong quantity: the question asks for the change, and you compute the total.
- Mixed units - minutes against hours, grams against kilograms.
- Rounding mid-calculation and still expecting the exact option.
- Treating 'possibly true' as 'must be true' in a syllogism.
- Overfitting a series rule to one pair of terms instead of verifying across all of them.