Logical Reasoning and Mathematics Essentials

Blood-relation questions should be drawn, not memorised. Mark parent-child links vertically, marriage links horizontally and siblings on the same level. Do not assume gender unless the word gives it, such as mother, father, brother, sister, son or daughter. Paternal means through the father and maternal means through the mother. In a compressed statement like "A is the only daughter of B's father", first locate B's father, then his only daughter, and only then state A's relation to B.

Number series and alphabet series reward the same habit: test the rule on every given term. Number series may use constant difference, increasing difference, multiplication or division, squares, cubes, primes, alternating operations, digit sums or mixed pairs. Alphabet series may move forward or backward by fixed gaps, use two interleaved tracks, pair letters from opposite ends of the alphabet, or combine letters with numbers. Convert letters to positions only when it makes the pattern clearer; A = 1, B = 2 and Z = 26 is a tool, not a rule by itself.

Clock questions are rate questions. The minute hand moves 6 degrees per minute and the hour hand moves 0.5 degree per minute, so their relative speed is 5.5 degrees per minute. At 4:20, the minute hand is at 120 degrees and the hour hand is at 130 degrees, so the smaller angle is 10 degrees. Calendar questions use odd days: a common year gives 1 odd day and a leap year gives 2 odd days. For month-based questions, add the odd days month by month and reduce by multiples of 7.

Mental and analytical ability questions should be converted into a small table, family tree, line diagram or equation before options are checked. The safest final check is simple: every clue must be used exactly once and no answer should depend on an assumption that the question did not give.