In a certain code language, ‘A + B’ means ‘A is the son of B’; ‘A # B’ means ‘A is the sister of B’; ‘A × B’ means ‘A is the wife of B’; and, ‘A @ B’ means ‘A is the father of B’. Based on the above, how is M related to T if ‘M # N @ L × P + T’?
- (a)Son’s wife’s father’s mother
- (b)Son’s wife’s father’s sister
- (c)Son’s wife’s father
- (d)Son’s wife’s sister
Answer
Why
Correct — B. Rule: translate the chain left to right, one symbol at a time, then walk it backwards from T.
M # N: M is the sister of N.
N @ L: N is the father of L.
L × P: L is the wife of P.
P + T: P is the son of T.
Now start where the question starts, at T. P is T's son. L is that son's wife. N is L's father. M is N's sister.
Chain it together and M is T's son's wife's father's sister — option (b).
Why the others are wrong
- (a)Son’s wife’s father’s mother — Son's wife's father's mother would put the last person a generation above N. The chain's final symbol is M # N, which makes M the sister of N, not the mother of N.
- (c)Son’s wife’s father — Son's wife's father stops at N. N is indeed L's father, but the question asks about M, who sits one link further along the chain.
- (d)Son’s wife’s sister — Son's wife's sister would make M a sister of L. M is the sister of N, and N is L's father, so M is L's paternal aunt rather than her sister.
Concept
A coded blood-relation item gives you a private dictionary of symbols and one expression written in it. Two habits cost marks here.
The first is reading the expression backwards. A + B fixes A's role and says nothing about B's, so the chain must be translated in printed order.
The second is answering in the wrong direction. How is M related to T means you begin at T and travel to M, which is the reverse of the order in which you read the chain.
The options are written as possessive chains, so the safest finish is to build one of your own before looking at them.
Starting from T and stepping through son, son's wife, her father, his sister lands on the wording of one option without any guesswork.
Key facts
- A + B means A is the son of B, so the symbol always describes the person on the left.
- In this chain M is the sister of N, N is the father of L, L is the wife of P, and P is the son of T.
- T's son is P, so every relation asked about M runs through P first.
- M is the sister of L's father, which in ordinary English makes M the paternal aunt of L.
Study next
Common traps
- Translating the chain from right to left and inverting every relation
- Answering how T is related to M when the question asked the reverse
- Reading a sister link as a parent link because both attach to the same person
Read the dictionary printed above the chain rather than one you remember, because it moves between shifts without warning.
Sometimes it repeats verbatim: 10 Sep 2024, 16:00, Reasoning Q.2 and 26 Sep 2024, 12:30, Reasoning Q.14 both use + mother, − brother, × wife, ÷ father.
Sometimes it shifts by a single symbol: 25 Sep 2024, 12:30, Reasoning Q.20 and 12 Sep 2024, 12:30, Reasoning Q.8 agree that + is son, − is wife and × is brother, but ÷ is mother in the first and daughter in the second.
Related PYQs
No directly related past PYQ was found.