General Aptitude, Reasoning and Quantitative Ability
This section rewards speed and accuracy across series, coding, reasoning and quantitative problems at roughly matriculation level. The questions are not hard, but negative marking punishes careless computation.
Core rules
- Work and rate: combined rate is the sum of reciprocals, so time together = xy/(x + y).
- Average speed over equal distances is the harmonic mean 2xy/(x + y), not the arithmetic mean.
- A rise of x% followed by a fall of x% leaves a net loss of x²/100 per cent.
- In syllogisms accept only definite conclusions; a possibility is not a conclusion unless the option states it as one.
- For series, check differences first, then ratios, then squares and primes, then alternating patterns.
- For blood relations, draw the family tree and fix each person's gender before reading the options.
- In data interpretation, compute only the ratio or percentage asked, not the whole table.
Worked example
A fills a tank in 12 hours, B in 18 hours. Together they fill 1/12 + 1/18 = 3/36 + 2/36 = 5/36 of the tank per hour, so the tank fills in 36/5 = 7.2 hours. With a leak emptying at 1/36 per hour the net rate is 4/36, giving 9 hours. Writing the reciprocal sums before touching a calculator prevents most slips.
Traps
Averaging speeds arithmetically over equal distances; arguing from 'some A are B' to 'all B are A'; miscounting squares or triangles in a figure-counting item; and sinking time into a long data set before the quick series questions.