SSC CGL 2025 Tier-I · 16 September 2025, Shift 3 · General Intelligence and Reasoning · Question 15 of 75

We transcribed this text from the pictures on a candidate's response sheet for this shift; the answer is the key SSC colour-marked on that sheet. Solution last reviewed 13 September 2026.

Where this paper and its answers come from

SSC does not publish CGL question papers or a public answer key. From 2025 the candidate response sheet prints every question and option as a picture, so the text here is transcribed from those pictures for this shift and checked against them independently; where the layout carries meaning, the picture is shown as well. Each answer is the key SSC colour-marked on that sheet. SSC released a tentative key for challenge and later its final one, both only to candidates behind a login, and the sheet does not say which of the two it carries. The solutions are written by UnlockIAS.

P is the mother of Q. Q is the sister of R. How is P related to R?

(a)Aunt
(b)Mother
(c)Grandmother
(d)Cousin

Answer

Why

Correct — B.
Rule: brothers and sisters share their parents.

P is the mother of Q.
Q is the sister of R, so Q and R are children of the same parents.
So P is R's mother as well → option (b).

R's gender is not given, and it does not matter: P is R's mother either way.

Why the others are wrong

(a)
Aunt — Aunt would make P the sister of R's parent. P is the mother of Q, and Q is R's sister, so P is R's parent herself.
(c)
Grandmother — Grandmother is one generation too far up. It needs P to be the mother of R's parent, but P is the mother of R's sister, so P is R's parent.
(d)
Cousin — Cousin puts P in R's own generation, as the child of R's aunt or uncle. P is the mother of R's sister, one generation above R.

Concept

Blood-relation questions treat a brother or sister as a child of the same parents. So the mother of one sibling is the mother of the other.

Draw it as a tree: P at the top, Q and R side by side beneath, with a line from P down to both. P is a woman, so the relation is mother whether R is a son or a daughter.

The key reads 'sister' in the usual way, as a sister with the same parents. Nothing in the question points to a half-sister, so none should be assumed.

Key facts

Siblings share parents, so the mother of Q is also the mother of Q's brother or sister.
An aunt is a parent's sister.
A grandmother is a parent's mother, two generations up.
A cousin is the child of a parent's brother or sister, in your own generation.

Study next

Coded blood relations, where symbols stand for mother, father, brother and sisterChains of three or more relations drawn as a family treeIn-law relations such as husband's sister and wife's brother

Common traps

Choosing Aunt because P is a woman one generation above R, without checking that P is R's own parent
Stopping to work out R's gender, which the question never gives and the answer never needs

17 Sep 2024, 09:00, Reasoning Q.11 turns on the same sibling step: C is E's sister and A's daughter, so A is E's parent too, and G is keyed as A's wife's brother.

Reasoning Q.21 of this shift asks it in code: P ÷ Q − R makes P the father of Q and Q the sister of R, keyed P is R's father.

Related PYQs

No directly related past PYQ was found.

Topic: Problem Solving — all 123 SSC CGL questions on it, every solved shift.