Aptitude and English
This domain combines quantitative aptitude, data interpretation and logical reasoning with English usage - the sections where speed and precision, not deep theory, decide the mark.
Core rules
- Percentages: percentage change = (new − old) ÷ old. Percentage points and percentages are different; a rise from 10% to 13% is 3 percentage points but a 30% increase.
- Ratios and proportions: convert to a common base before comparing; a ratio a:b means a/(a+b) of the total.
- Work and rate problems: add rates, not times. If A finishes in 6 days and B in 12, combined rate = 1/6 + 1/12 = 1/4, so 4 days.
- Data interpretation: check units (thousands, millions, Rs) and read whether a graph shows values or percentages before computing.
- Reasoning: number series usually involve constant differences, squares/cubes or alternating patterns; syllogisms should be tested only against the stated premises.
- English: subject–verb agreement, with "neither…nor" the verb agrees with the nearer subject; correct tense sequencing; prepositions; articles; synonyms, antonyms and one-word substitution.
Worked example
Audit fees rose from Rs 4.20 million to Rs 5.04 million, and total expenditure is Rs 42 million. Fee increase = (5.04 − 4.20) ÷ 4.20 = 0.84 ÷ 4.20 = 20%. Fee as a share of total expenditure = 5.04 ÷ 42 = 12%. The base differs for each question, which is exactly where candidates slip.
Traps that cost marks
- Using the new value as the base for a percentage increase.
- Missing unit mismatches between a table in millions and an option in rupees.
- Overlooking "not" and "except" in the question stem.
- In English, applying "neither…nor" with a plural verb while the nearer subject is singular.