Reasoning Ability - Lesson 17

Draw the tree, trace the path.

Every blood-relations question reduces to two moves: map the family into a labelled tree, then follow the path between two people. Speed comes from never guessing gender.

Learning time
20 min · self-paced
Exam weight
2–4 questions / set
Sections
11 modules
AMBFCFD? 
Topic map

9 sections, in the order they actually build on each other.

A 1:1 progression from statement basics to revision and next actions, tuned for practical exam speed.

Topic 01

Core concepts

Direct relations, sides, generations, gender.

Topic 02

The 6-step approach

Decode, list, draw, gender, trace, check.

Topic 03

Question types

Direct, chain, coded, pointing, puzzle.

Topic 04

Worked examples

Three levels, stepped through the method.

Topic 05

Common traps

Gender guessing, direction, side mix-ups.

Topic 06

Tips & shortcuts

Box-and-line notation and 2-hop pairs.

Topic 07

Cheatsheet

2-hop shortcuts, coded symbols, gender rules.

Topic 08

Mini practice

Draw-then-trace questions with feedback.

Topic 09

What to do next

Practice, build a test, review mistakes.

Foundation - 01

Eight concepts behind every family tree.

Tap any concept to read its definition and how to apply it when tracing the tree.

Interactive
Direct relations

A direct relation is stated explicitly with no intermediate person — "A is the father of B". Draw it as a single link from A to B.

Use it
One-step links: father, mother, son, daughter, brother, sister.
Watch out
Confirm gender and generation from the text before placing a person.
AMB?
Try it yourself

Trace a relationship one hop at a time.

Pick two moves on the family tree and let the chain resolve the final relation. This mirrors the exact exam habit: never read a long relation in one gulp.

Live sandbox
Go to your...
...then their...
Your father's father is your Grandfather.
YouFatherFather
Grandfather
Resolve the chain from left to right, one hop at a time, and the final relation becomes much safer to read.
Method - 02

The 6-step approach.

Follow this sequence every time. Speed comes from repeating the same reliable loop.

STEP 1

Decode the legend

If the question is coded, write the legend as a mini-table before reading. Never decode mid-chain.

STEP 2

List all persons

Scan the passage; list every name. Note gender only where explicitly given. Circle unknowns.

STEP 3

Draw statement-by-statement

Process one sentence at a time. Add each person to the correct generation row and branch.

STEP 4

Assign genders

Fill missing genders from pronouns and relation words. Use M / F labels on each box.

STEP 5

Trace the asked path

Start from the first-named person, follow the tree to the second, and name the relation.

STEP 6

Check the direction

Confirm it asked "how is X related to Y", not the reverse. Flip the relation if needed.

Pro tip. Grandfather and grandson are the same path read in opposite directions — the direction check in step 6 is where most careless marks are saved.
Question types - 03

Identify the format first, then run the matching pattern.

Five recurring formats. Spotting which one you’re in tells you exactly how to set up the tree.

Direct relation

What it looks like
One sentence, two people, one relation. "A is the mother of B. What is B to A?"
How to solve
Draw the single link and reverse the stated relation.
Mini example. A mother of B → B is A’s son/daughter.
Trap: "A related to B" and "B related to A" can differ — check direction.

Chain relation

What it looks like
Three or more linked statements across generations.
How to solve
Number the statements; draw each, then trace the full path.
Mini example. A father of B, B sister of C → A is C’s father.
Trap: Losing your place mid-chain — number before drawing.

Coded relation

What it looks like
Relations hidden behind +, −, ×, ÷ symbols.
How to solve
Write the full legend table, split into pairs, then draw.
Mini example. P + Q means P is father of Q.
Trap: Skipping the legend and decoding mid-tree.

Pointing / introduction

What it looks like
"Pointing to a photo, he said … son of my mother’s only son."
How to solve
Anchor on the speaker; expand the phrase outward.
Mini example. Mother’s only son = the speaker (or his brother).
Trap: Reading the relation from the wrong perspective.

Family tree puzzle

What it looks like
A larger family with many members and several questions.
How to solve
Build one complete tree, then answer every sub-question from it.
Mini example. Find how each pair is related.
Trap: Re-drawing per question instead of reusing one tree.
Worked examples - 04

Watch three problems solved step by step.

Three difficulty levels. Step through manually or replay.

Problem
QuestionA is the father of B. B is the sister of C. C is the mother of D. How is A related to D?
Draw and trace
AMBFCFD?
Step 1. List persons: A (M, father), B (F, sister), C (F), D (?). A is G+1; B and C share G0; D is G−1.
1 / 5
Common traps - 05

The 5 traps that show up in nearly every paper.

Trap 01 - Guessing gender from a name
Treat "Robin" or "Kim" as definitely male or female.
Assign gender only when a relation word or pronoun confirms it. Use "?" until then.
Trap 02 - Paternal vs maternal mix-up
Blur "mother’s brother" with "father’s brother".
Tag each branch P or M from the first sentence that names a side.
Trap 03 - Reversing the direction
Answer "B to A" when it asked "A to B".
Circle both names and draw a directional arrow; start at the first name.
Trap 04 - Assuming "only child"
Close a sibling branch that wasn’t stated as only.
Keep sibling branches open-ended unless it says "only son/daughter".
Trap 05 - Skipping the legend
Dive into a coded tree without decoding.
Write the full 3-column legend (symbol / direction / relation) first.
Tips - 06

Tips & shortcuts.

Small tactical habits that improve both accuracy and pace.

TIP 01
Box-and-line notation

Boxes for people, dashed line for couples, vertical lines for parent–child, flat bar for siblings.

TIP 02
Label gender immediately

Write M or F on each box the moment the text confirms it.

TIP 03
Work backward from anchors

For "grandfather’s only son", start at grandfather, expand down, then identify.

TIP 04
Number long chains

In 4+ statement chains, number each statement before drawing.

TIP 05
Split coded strings into pairs

Break "A @ B # C" into (A@B), (B#C) and process one pair at a time.

TIP 06
Sanity-check the relation

If your answer sounds invented, re-check the path direction — it should be a standard relation.

TIP 07
Memorise the 2-hop pairs

Father’s father = grandfather, mother’s brother = maternal uncle, husband’s sister = sister-in-law.

Mini practice - 07

Mini practice.

Draw then trace. Instant explanation for every question.

Question 1 of 4Easy
A is the mother of B. B is the brother of C. How is A related to C?
Revision - 08

Quick-reference cheatsheet.

Your last-minute pass before mocks and exam slots.

2-hop shortcuts
RelationEquals
Father’s fatherGrandfather
Mother’s motherGrandmother
Mother’s brotherMaternal uncle
Father’s sisterPaternal aunt
Sibling’s sonNephew
Son’s wifeDaughter-in-law
Coded symbols (verify per question)
+husband / father of
wife / mother of
×brother of
÷sister of
Last-minute reminders
  • 01Never guess gender — leave it "?" until confirmed.
  • 02Always check which direction the question asks.
  • 03Decode the coded legend completely before drawing.
  • 04Draw sibling branches open-ended unless "only" is stated.
  • 05Label each person’s generation as you place them.
  • 06Reuse one tree for every sub-question.
What's next - 09

You've finished the lesson. Time to lock it in.

Practice Blood Relations questions

Direct, coded, and pointing sets with instant explanations and a mistake notebook. ~18 minutes.

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Build a reasoning test

Choose Blood Relations under Reasoning to simulate exam pressure.

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Review your mistakes

Filter your notebook by topic to focus on Blood Relations errors.

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