Analytical Ability
Clockwise-Direction Mnemonic — Remember "NEWS" clockwise from top: North→East→South→West. For 45° angles add NE, SE, SW, NW between them. Right turn = clockwise, Left turn = anti-clockwise.
Blood Relations Gender Trap — Brother's/Sister's daughter = Niece (female); Brother's/Sister's son = Nephew (male). Mother's/Father's brother = Uncle; their wives = Aunt. Spouse's siblings = Brother/Sister-in-law.
Coding Pattern Rule — In letter-shift coding, write alphabet positions (A=1, Z=26). If CAKE=3-1-11-5 becomes FBNH, check: +3 shift. Apply same shift to decode unknown words immediately.
Sequence Gap Tricks — Prime series: 2,3,5,7,11,13... Perfect squares: 1,4,9,16,25,36... Cubes: 1,8,27,64,125... Memorize first 15 of each; 80% sequence questions use these foundations.
Venn Diagram Formula — For two sets: n(A∪B) = n(A) + n(B) - n(A∩B). For three sets: add all three, subtract all pairs, add back the triple intersection. "Only A" = n(A) - overlaps.
Calendar Day Formula — Odd days = Total days mod 7. 365 days = 1 odd day; 366 = 2 odd days. Jan 1, 2000 was Saturday; count odd days forward to find any date's day quickly.
Seating Arrangement Anchor — Always fix one person's position first (usually mentioned as reference). Mark clockwise/anti-clockwise clearly. "Opposite" means diameter across; "adjacent" means immediate neighbor.
Data Sufficiency Template — Check: (A) Statement 1 alone sufficient? (B) Statement 2 alone sufficient? (C) Both together needed? (D) Each alone sufficient? (E) Even together insufficient? Follow this order always.
Mathematical Ability
Divisibility by 11 Rule — Alternating digit sum: subtract odd-position digits from even-position digits. If result is 0 or divisible by 11, the number is divisible by 11. Example: 121→(1+1)−2=0✓
Percentage-Fraction Equivalents — Memorize: 12.5%=⅛, 16.67%=⅙, 20%=⅕, 25%=¼, 33.33%=⅓, 50%=½, 66.67%=⅔, 75%=¾. Saves calculation time; directly convert in profit/loss problems.
Profit/Loss Shortcut — If cost price CP and marked price MP: Discount on MP, Profit on CP. Two successive discounts d1%, d2%: Net = (d1+d2−d1×d2/100)%. Not simple addition!
Compound Interest Trick — For 2 years: CI−SI = SI²/(100×P) where P=principal. For 3 years at same rate, extra CI over SI = 3×(R/100)²×P + (R/100)³×P.
Quadratic Sum-Product — For ax²+bx+c=0, roots α,β: Sum α+β = −b/a, . If asked root values, use these first before quadratic formula to save time.