Q36·CSAT · Prelims 2022
Deducing correct relations from a family tree logic puzzle
ReasoningBlood RelationsFactual single● Medium
Question
P, Q, R, S, T and U are six members of a family. R is the spouse of Q. U is the mother of T and S is the daughter of U. P's daughter is T and R's son is P. There are two couples in the family. Which one of the following is correct?
Options
a
Q is the grandfather of T
b
Q is the grandmother of T
c
R is the mother of P
dAnswer
T is the granddaughter of Q
Explanation
Map out the family tree generation by generation:
1"R is the spouse of Q" \implies R and Q form Couple 1 (Gen 1).
2"R's son is P" \implies P is a male in Gen 2, child of R and Q.
3"P's daughter is T" \implies T is a female in Gen 3, child of P.
4"U is the mother of T" \implies Since P is T's father, U must be P's wife. P and U form Couple 2 (Gen 2).
5"S is the daughter of U" \implies S is female in Gen 3, sibling to T.
Now evaluate the options:
(a) & (b): Q is a grandparent, but the text provides absolutely no data to determine whether Q is male or female. Thus, Q cannot be definitively labeled a grandfather or grandmother.
(c): R's gender is also unknown. R could be the father or mother of P.
(d): T is definitively female (P's daughter) and is the child of P, who is the son of Q. Therefore, T is undeniably the granddaughter of Q.
In blood relation puzzles, track the gender of every individual strictly. Reject any conclusion that assigns a gender-specific title (like grandfather or mother) to a person whose sex was never stated.
Answer: (d).
Question details
Year
2022
Paper
CSAT
Question
Q36
Section
Logical & Analytical Reasoning
Sub-topic
Blood Relations
Type
Factual single
Difficulty
Medium
Source hint
P, Q, R, S, T, U family tree
Same sub-topic — other years
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