Blood Relations | Class 7 reasoning — School Syllabus

What you'll learn

Use standard family relationship terminology correctly
Draw a family tree from given information
Decode coded relationship statements
Solve chain problems to find the relationship between two people

Key concepts

Core Family Terms

Term	Meaning
Paternal	Related through the father's side
Maternal	Related through the mother's side
Sibling	Brother or sister
Spouse	Husband or wife
Ancestor	Any person from a previous generation (parent, grandparent, etc.)
Descendant	Any person from a later generation (child, grandchild, etc.)

Generation levels:

+2: Grandparents
+1: Parents, Aunts, Uncles
0: Self, Siblings, Cousins
−1: Children, Nieces, Nephews
−2: Grandchildren

Standard Relationship Reference Table

Relationship	Who they are
Father's father	Grandfather (paternal)
Mother's father	Grandfather (maternal)
Father's brother	Uncle (Paternal Uncle / Chacha/Tau)
Mother's brother	Uncle (Maternal Uncle / Mama)
Father's sister	Aunt (Bua)
Mother's sister	Aunt (Mausi)
Uncle's/Aunt's child	Cousin
Sibling's son	Nephew
Sibling's daughter	Niece
Son's wife	Daughter-in-law
Wife's/Husband's brother	Brother-in-law
Wife's/Husband's sister	Sister-in-law

Drawing a Family Tree

Always draw a tree when more than two people are involved.

Symbols:

Square (□) = Male
Circle (○) = Female
Horizontal line (—) = Married
Vertical line (|) = Child of
Double horizontal line (=) = Siblings

Worked Example: "Pointing to a girl, Ram says, 'She is the daughter of the wife of my father's only son.' Who is the girl to Ram?"

My father's only son → Ram himself
Wife of Ram → Ram's wife
Daughter of Ram's wife → Ram's daughter
Answer: Ram's daughter

Tip: Always start from the person being described and work backward one step at a time.

Coded Relationship Problems

In these problems, +, −, ×, ÷, or other symbols replace relationship words.

Given key: A + B means A is the father of B; A − B means A is the mother of B; A × B means A is the brother of B; A ÷ B means A is the sister of B.

Worked Example: P + Q − R — What is R to P?

P + Q → P is the father of Q
Q − R → Q is the mother of R (Q is female)
So P is the father, Q is the mother → R is their child → R is P's son or daughter (child/grandchild? No — Q is the child of P and also the mother of R → R is P's grandchild)

Answer: R is the grandchild of P.

Solving Chain Problems — 4-Step Method

Problem: A is the brother of B. B is the mother of C. C is the sister of D. How is A related to D?

Step	Person	Relation Derived
1	A is B's brother	A and B are siblings
2	B is C's mother	C is B's child, so C is A's nephew/niece
3	C is D's sister	D is also B's child, so D is A's nephew/niece
4	Final answer	A is D's uncle

Worked Example 2: "X's mother is Y's grandmother. Y has no siblings. Z is Y's mother. How is X related to Z?"

X's mother is Y's grandmother
Y's mother is Z → Z is Y's mother → Y's grandmother is Z's mother
So X's mother = Z's mother → X and Z are siblings
Answer: X is Z's brother or sister

Common Traps

Gender is not always given — don't assume.
"Only child" rules out siblings — use this to simplify.
"My father's only son" = me (if I am male) — a classic trap.
Son-in-law / daughter-in-law confuse direction — remember they marry IN to the family.

Quick check

A man pointing to a photograph says, "She is the daughter of my grandfather's only son." How is she related to him?
If A is the brother of B, C is the mother of A, and D is the father of C — how is D related to B?
P + Q means P is the parent of Q. R − S means R is the sibling of S. If M + N − O, how is O related to M?
Who is a maternal uncle's daughter to you?
"The woman in the photo is the only daughter of my mother-in-law's husband." What is she to the speaker?

Open the Practice tab for graded questions on Blood Relations.