Mental Ability, Reasoning, and Quantitative Aptitude
This domain checks speed and accuracy in series, coding-decoding, data interpretation, arithmetic, and analytical reasoning. The exam expects clean method, not guesswork: identify the pattern, write the rule, and test it on one or two terms before choosing an option.
Core rules
- Number series: check differences, ratios, squares, cubes, alternating patterns, and two-tier differences.
- Coding-decoding: note letter shifts, reversals, position sums, and word-to-number mappings.
- Ranking: total = position from left + position from right - 1.
- Data interpretation: read units, totals, and percentages; compare like with like.
- Arithmetic: percentages, ratio, average, time-work, and simple interest.
Worked example
In a row, Ravi is 12th from the left and 18th from the right. Reasoning: Ravi is counted twice, once in each position, so total = 12 + 18 - 1 = 29 children. If the question asks how many children are to Ravi's right, the answer is 18 - 1 = 17, not 18.
Traps
- Forgetting the overlap in ranking questions and adding the two positions.
- Treating percentage points as percent change; a rise from 20% to 25% is 5 percentage points, not 5%.
- Assuming a series is arithmetic when it is alternating or based on squares.
- Ignoring units in data interpretation, such as lakh versus crore.
- In coding, applying a shift to the original letters but mixing forward and backward shifts.
- Overcomputing: options often differ by one clear step, so estimate before long calculation.