Types of Reasoning
| Type | Description |
|---|---|
| Deductive | Moves from general premises to a specific, certain conclusion (if premises are true, conclusion must be true) |
| Inductive | Moves from specific observations to a general, probable conclusion |
| Analogical | Draws a conclusion based on similarity between two situations |
| Abductive | Infers the most likely explanation from incomplete evidence |
Number Series, Letter Series, Codes and Relationships
Number series
Identify the rule connecting consecutive terms — a constant difference (arithmetic), constant ratio (geometric), a difference-of-differences pattern, or a pattern like n² + n / n² − n.
Series: 0, 2, 6, 12, 20, 30, …, ? — each term equals n² + n for n = 0,1,2,3,4,5. The next term (n = 6) is 6² + 6 = 42.
Letter series
Letters are usually mapped to their position in the alphabet (A = 1 … Z = 26) and the same arithmetic logic as number series is applied — e.g. a series that adds +1, +2, +3, +4… to successive letters.
Codes and relationships
Coding-decoding questions substitute letters/numbers for other letters/numbers using a hidden rule (shift by a fixed number of places, reversal, substitution) that the candidate must detect from a given example and then apply to a new word.
Mathematical Aptitude
| Topic | Core formula / idea |
|---|---|
| Fractions | Comparing, adding, and simplifying parts of a whole; converting to a common denominator |
| Time & Distance | Speed = Distance ÷ Time; relative speed for meeting/overtaking problems |
| Ratio & Proportion | a:b = c:d ⇒ a×d = b×c (cross-multiplication) |
| Percentage | Percentage = (Part ÷ Whole) × 100 |
| Profit & Loss | Profit % = (Profit ÷ Cost Price) × 100; Loss % similarly on Cost Price |
| Interest & Discount | Simple Interest = (P × R × T) ÷ 100; Discount = Marked Price − Selling Price |
| Averages | Average = Sum of observations ÷ Number of observations |
Most Paper I quantitative questions test the concept, not heavy calculation — look for the shortest arithmetic path (percentages as fractions, ratios in lowest terms) before solving.