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4. Blood Relations, Direction Sense and Ranking

CSS GSA — Paper 7, Part-II, Section VII, Sub-topic 4 (Blood Relations, Direction Sense and Ranking)

Past Paper Weightage

  • Moderate-high — blood relation and direction-sense puzzles appear regularly and are fast marks once the shortcut notation is learned.

Blood Relations — Shortcut Method

  • Trick: Draw a simple family tree/chart as you read the clue, rather than tracking relationships purely in your head. Use "+" for male, "−" for female if gender is known, and simple arrows for "parent of."
  • Key phrase decoder (memorize these instantly):
    • "My father's only son" (when I am male, with no brothers) = myself
    • "My mother's only daughter" (when I am female, no sisters) = myself
    • "My grandfather's only son" = my father (if the grandfather has only one son)
    • "Son of my father's sister" = my cousin

Worked Example (Blood Relation)

  • Pointing to a photo, Ahmed said, "She is the daughter of my grandfather's only son."
    • Step 1: Decode "my grandfather's only son" — using the key-phrase shortcut above, since Ahmed's grandfather has only one son, and Ahmed descends from that grandfather, the "only son" must be Ahmed's own father.
    • Step 2: "Daughter of my father" = Ahmed's own sister.
    • Step 3: Answer: the woman in the photo is Ahmed's sister.

Direction Sense — Shortcut Method

  • Trick: Sketch a simple compass cross (N up, S down, E right, W left) and physically trace each leg of the journey on it — never try to track turns purely mentally.
  • Turn rule: Facing North, a right turn faces you East; a left turn faces you West. Facing East, a right turn faces South; a left turn faces North. (Rotate the compass 90° in the turn's direction each time.)
  • Final-distance shortcut: after plotting all legs, opposite-direction legs (e.g., a North leg and a South leg) cancel out by their smaller-minus-larger amount — you don't need to compute distance with the Pythagorean theorem unless the final two remaining legs are perpendicular to each other.

Worked Example (Direction)

  • A man walks 5 km North, turns right, walks 3 km, turns right again, walks 5 km. Find his distance and direction from the start.
    • Step 1: Leg 1: 5 km North. Turning right while facing North means now facing East — Leg 2: 3 km East. Turning right again while facing East means now facing South — Leg 3: 5 km South.
    • Step 2: The 5 km North and 5 km South legs are opposite and equal — they fully cancel out.
    • Step 3: Only the 3 km East leg remains uncancelled. Final answer: 3 km East of the starting point.

Ranking/Ordering — Shortcut Method

  • Trick: Draw a single horizontal line and place people/items on it according to each clue, adjusting as new clues arrive, rather than solving algebraically.
  • Convert "X is 3rd from the top in a class of 30" style clues into "X's rank from the bottom = (total − rank from top + 1)" instantly using this formula.

Worked Example (Ranking)

  • In a class of 40 students, Sara ranks 12th from the top. Find her rank from the bottom.
    • Step 1: Apply the formula: rank from bottom = total − rank from top + 1.
    • Step 2: Plug in: 40 − 12 + 1 = 29.
    • Step 3: Sara ranks 29th from the bottom.

MCQ Traps

  • "Only son/daughter" phrasing is the key to unlocking most blood-relation puzzles — always look for it first
  • In direction puzzles, a common trap is forgetting that "right" and "left" turns are relative to the direction currently being faced, not fixed compass directions

Self-Test Questions

  1. "Pointing to a man, a woman says, 'His mother is the only daughter of my mother.'" How is the woman related to the man?
  2. A woman walks 6 km South, turns left, walks 4 km, turns left again, walks 6 km. Find her distance and direction from the start.
  3. In a row of 25 people, Bilal is 9th from the left. Find his position from the right.

Past-Paper MCQs (FPSC)

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The FPSC MCQ papers you shared (2024 and 2025) had no direct direction, blood-relation or ranking question.

Past-Paper Questions with Answers (FPSC)

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Every question below appeared in the FPSC papers you shared; the year and question number are in each title. Answers are worked out by me. Direction and ranking questions appear almost every year.

  • CSS 2024 Q7(a): A man walks round a right-angled triangle (base 4 km, hypotenuse 5 km), continues 6 km, turns 90° and walks 8 km. Distance travelled and distance from the start? (5)
    1. Third side = 3 km; one round = 4 + 5 + 3 = 12 km
    2. Distance travelled = 12 + 6 + 8 = 26 km
    3. The last two legs are at right angles: √(6² + 8²) = 10 km from the start
  • CSS 2022 Q6(a): Aslam walks 110 m east, turns right and walks 40 m, turns right and walks 50 m, turns right and walks 120 m. How far is the bench from his house? (5)
    1. Start (0, 0). East 110 → (110, 0)
    2. Right (south) 40 → (110, −40)
    3. Right (west) 50 → (60, −40)
    4. Right (north) 120 → (60, 80)
    5. Distance = √(60² + 80²) = 100 m
  • CSS 2021 Q7(a): A child goes 90 m east, turns right and goes 20 m, turns right and goes 30 m (uncle's house), then 100 m north. How far from the start? (5)
    1. (0, 0) → (90, 0) → (90, −20) → (60, −20) → (60, 80)
    2. Distance = √(60² + 80²) = 100 m
  • CSS 2018 Q6(B): A car travels 3 km south, 4 km west, 5 km north and 2 km south-east. How far is it from the start? (5)
    1. South 3 and north 5 leave 2 km north; west 4 km → position (−4, 2)
    2. South-east 2 km adds (+√2, −√2) ≈ (+1.41, −1.41) → (−2.59, 0.59)
    3. Distance = √(2.59² + 0.59²) ≈ √7.03 ≈ 2.65 km (exactly √(24 − 12√2))
  • CSS 2017 Q8(C): A man walks 2 km north, 10 km east, 3 km north and 2 km east. How far is he from the start? (5)
    1. Total north = 2 + 3 = 5 km; total east = 10 + 2 = 12 km
    2. Distance = √(5² + 12²) = 13 km
  • CSS 2020 Q7(a): Mushtaq weighs 4 times Pervaiz; Pervaiz double Ehsan; Ehsan half of Umair; Umair half of Saleem. (i) heaviest, (ii) second heaviest, (iii) lowest, (iv) equal weights, (v) descending order. (5)
    1. Let Ehsan = e: Pervaiz = 2e; Mushtaq = 8e; Umair = 2e; Saleem = 4e
    2. (i) Heaviest Mushtaq; (ii) second Saleem; (iii) lowest Ehsan; (iv) equal Pervaiz and Umair
    3. (v) Mushtaq > Saleem > Pervaiz = Umair > Ehsan
  • CSS 2016 Q11(b): Ahmad weighs 3 times Ali; Ali 5 times Akbar; Akbar half of Nasir; Nasir half of Shehbaz. Find the heaviest, lightest and the descending order. (5)
    1. Let Akbar = a: Ali = 5a; Ahmad = 15a; Nasir = 2a; Shehbaz = 4a
    2. (i) Heaviest Ahmad; (ii) lightest Akbar
    3. (iii) Shehbaz is lighter than Ahmad and Ali; (iv) heavier than Nasir and Akbar
    4. (v) Ahmad > Ali > Shehbaz > Nasir > Akbar
  • CSS 2018 Q8(A): Baker is directly behind a stolen car, Lopez behind Baker, O'Malley behind Lopez. Reinhart makes a U-turn and joins behind Lopez. Baker pulls alongside the driver's side and Lopez the other side. Who is directly behind the vehicle? (5)
    1. Order behind the car: Baker, Lopez, Reinhart, O'Malley
    2. Baker and Lopez move to the sides
    3. The next in line is Reinhart
  • CSS 2025 Q8(c): A six-member family (A to F) has two fathers, three brothers and a mother. C is F's sister; B is the brother of E's husband; D is the father of A and the grandfather of F. Who is E's husband? (5)
    1. D is the grandfather of F and father of A, so A is F's parent (and a father)
    2. The two fathers are D and A; so the one mother is E, and she is F's mother
    3. Therefore E's husband is A (B is A's brother; C and F are A and E's children)
  • CSS 2017 Q7(D): A told B that C is his father's nephew. D is A's cousin but not the brother of C. What is D to C? (5)
    1. C is A's father's nephew, so C is A's cousin
    2. D is also A's cousin, but is not C's brother
    3. So D is C's sister (cousin from the same side)
    • This is the commonly accepted answer; the question gives no other clue

CSS Exam Perspective

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  • Most repeated areas: direction and distance (2017, 2018, 2021, 2022, 2024), weight/rank ordering (2016, 2020), family relations
  • Tip: plot every move on x–y axes; the answer is usually a 3-4-5 or 6-8-10 triangle