Blood Relations

Family tree and relationship problems

115 practice questionsPage updated 1 Sept 2026Reviewed by AISEA Editorial DeskPractice questions

Blood-relations questions ask you to trace family connections from precise statements. The fastest reliable method is to draw a small family graph, place generations in order, label gender and marriage links, and then follow the requested path. Do not rely on names or intuition: a child may be a son or daughter, a spouse link is not a blood link, and an incomplete set of facts can legitimately lead to ‘cannot be determined’.

Key formulas and rules

Parent of parent = grandparent; child of child = grandchild.

Sibling of a parent = aunt or uncle; child of a sibling = niece or nephew.

Child of a parent's sibling = first cousin.

Generation level: parent moves one level up, child moves one level down, and sibling or spouse stays at the same level.

Relation path = start person + follow each stated link in order + translate the final path from the requested perspective.

A coded relation is valid only when every operator is decoded exactly as defined in the question.

A relation is determined only when every family graph satisfying the clues gives the same answer.

Key concepts

Draw a family graph

Represent a parent-child link vertically and a spouse link horizontally. Put people from an older generation above their children and siblings on the same level. Add a gender label only when the statement gives one. The graph makes long phrases visible and reduces the chance of reversing a link.

Parse nested phrases from the inside out

For a phrase such as ‘the daughter of the wife of my grandfather's son’, resolve the innermost reference first, then move outward one link at a time. Replace each resolved phrase with a short label such as father, mother or aunt before continuing. Never skip a link in a chain.

Worked examples

Example 1

Pointing to a photograph, a man says, ‘She is the daughter of my father's only son.’ How is the man related to the girl?

Solution

Step 1: The speaker is a man and ‘my father's only son’ refers to the speaker himself.
Step 2: The girl is the daughter of the speaker.
Answer: The man is the girl's father.

Example 2

A woman introduces a man as the son of the brother of her mother. How is the man related to the woman?

Solution

Step 1: The brother of the woman's mother is her maternal uncle.
Step 2: The man's parent is that maternal uncle.
Step 3: The son of a maternal uncle is the woman's cousin.
Answer: Cousin.

Example 3

A is the brother of B, B is the sister of C, and C is the father of D. How is A related to D?

Solution

Step 1: A, B and C are siblings because A is B's brother and B is C's sister.
Step 2: C is D's father.
Step 3: A is the brother of D's father, so A is D's uncle.
Answer: Uncle.

Example 4

A woman points to a man and says, ‘He is the only son of my mother's father.’ How is the woman related to the man?

Solution

Step 1: The woman's mother's father is her maternal grandfather.
Step 2: His only son is the woman's maternal uncle.
Step 3: The woman is the daughter of the uncle's sibling, so she is his niece.
Answer: Niece.

Example 5

A is the son of B. C is the father of D. B is the daughter of C. How is A related to D?

Solution

Step 1: B is C's daughter, and A is B's son.
Step 2: D is also C's child because C is D's father.
Step 3: B and D are siblings, so A is D's nephew.
Answer: Nephew.

Example 6

If A plus B means A is the father of B, A minus B means A is the brother of B, and A times B means A is the sister of B, what does A minus B times C mean?

Solution

Step 1: A minus B means A is the brother of B.
Step 2: B times C means B is the sister of C.
Step 3: A is the brother of B, and B is the sister of C, so A is the brother of C.
Answer: A is C's brother.

Example 7

If M star P means M is the brother of P and P dollar N means P is the father of N, which expression shows that M is the uncle of N?

Solution

Step 1: M must be the brother of N's parent to be N's uncle.
Step 2: M star P makes M the brother of P.
Step 3: P dollar N makes P the father of N.
Answer: M star P dollar N. The symbols are placeholders here; in a real question, always use the definitions supplied with that question.

Example 8

M is the father of N, N is the son of O, and O is the mother of P. What is P's relation to M?

Solution

Step 1: M and O are both parents of N.
Step 2: O is also P's mother, but the clues do not say that M is P's father.
Step 3: P could be M's child or could be O's child from another relationship, and both possibilities fit the stated facts.
Answer: Cannot be determined.

Example 9

A is B's sister. C is B's mother. D is C's father. E is D's mother. How is A related to E?

Solution

Step 1: A is also C's child because A and B are siblings.
Step 2: D is C's father, so D is A's grandfather.
Step 3: E is D's mother, so E is A's great-grandmother.
Step 4: Therefore A is E's great-granddaughter.
Answer: Great-granddaughter.

Example 10

A woman says, ‘This man's wife's mother is the only daughter of my mother.’ How is the woman related to the man?

Solution

Step 1: The only daughter of the woman's mother is the woman herself, because the speaker is female.
Step 2: The man's wife's mother is therefore the speaker.
Step 3: The speaker is the mother of the man's wife.
Answer: Mother-in-law.

PedigreeNational Human Genome Research Institute · Checked 2 Sep 2026Supports: family relationship diagrams and reading connections across generations

Defining Family and HouseholdOpenStax · Checked 2 Sep 2026Supports: kinship charts, generation levels and parent, sibling and marriage links

What does it mean if a disorder seems to run in my family?MedlinePlus Genetics · Checked 2 Sep 2026Supports: recording family history as a family tree and tracing biological relationships

Blood Relations

Key formulas and rules

Key concepts

Draw a family graph

Parse nested phrases from the inside out

Track generations separately

Use gender clues exactly

Separate blood and marriage links

Interpret only son and only daughter carefully

Translate coded relations one operator at a time

Use shared parents and siblings correctly

Recognise underdetermined relations

Answer from the requested viewpoint

Verify the complete chain

Worked examples

Example 1

Example 2

Example 3

Example 4

Example 5

Example 6

Example 7

Example 8

Example 9

Example 10

Representative solved questions

Question 1

Question 2

Question 3

Common mistakes and useful habits

Sources and review notes

Ready to test your understanding?

Key formulas and rules

Key concepts

Draw a family graph

Parse nested phrases from the inside out

Track generations separately

Use gender clues exactly

Separate blood and marriage links

Interpret only son and only daughter carefully

Translate coded relations one operator at a time

Use shared parents and siblings correctly

Recognise underdetermined relations

Answer from the requested viewpoint

Verify the complete chain

Worked examples

Example 1

Example 2

Example 3

Example 4

Example 5

Example 6

Example 7

Example 8

Example 9

Example 10

Representative solved questions

Question 1

Question 2

Question 3

Common mistakes and useful habits

Sources and review notes

Ready to test your understanding?

Keep building the same skill family.