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

Correct — D. Take the four statements one at a time.

A is the sister of B, so A is female.
C is the daughter of A, so A is C's mother.
D is the sister of A, so D is female and of A's own generation.
E is the brother of C, so E is another child of A.

Rule: the answer must be read from E's side, because the question asks how D is related to E.

A is E's mother and D is A's sister, so to E she is his mother's sister → option (d).

Why the others are wrong

• (a)
  Mother’s mother — Mother's mother would make D the mother of A. The statement calls D the sister of A, which puts the two in the same generation.
• (b)
  Mother’s father — Mother's father is male, and it also lifts D a generation above A. D is A's sister, so neither part holds.
• (c)
  Mother’s brother — Mother's brother is male. The word sister fixes D as female, so the relation has to be mother's sister.

Blood-relation items are solved by drawing, not by reading. Put each generation on its own row, join a couple with a horizontal line and a child with a vertical one, and mark gender the moment a statement fixes it.

The relationship word itself fixes gender. Sister, daughter and mother make a person female; brother, son and father make a person male. A letter never described in gendered terms keeps an unknown gender.

Then answer in the direction asked. How D relates to E and how E relates to D are different questions with different answers.

Key facts

• A is female, since she is called the sister of B, and she is the mother of C.
• C and E are both children of A, because E is the brother of C.
• D is female and of A's generation, so D is the sister of E's mother.

Common traps

• Reading D as a generation above A because the options are full of grandparent phrases.
• Answering the reverse relation, how E is related to D.
• Assuming B must be male or must be a parent.

No directly related past PYQ was found.