Question

In a family of seven members, namely P1, P2, P3, P4, P5, P6, and P7, the following information is known:

• P4 is the sister of P7.

• P2 is the mother of P6's wife.

• P6 is the son-in-law of P3.

• P5 and P7 are the grandsons of P3.

• In the family, there are exactly: 2 fathers, 2 mothers, 2 brothers, 1 sister.
Based on the above information, what is the relationship between P1 and P4?

• A. Brother and Sister
• B. Mother and Daughter
• C. Husband and Wife
• D. Father and Son

Hint:

In family puzzles:

• Fix generations first.

• Identify gender-specific relations.

• Count family roles carefully.

• Use elimination to complete the tree.

Answer 1

The Correct Option is A

Step 1: Identify the eldest generation.
P5 and P7 are grandsons of P3, so P3 sits at the top as a grandparent.
Step 2: Place P3's spouse.
P2 is the mother of P6's wife, and that wife is P3's daughter, so P2 and P3 are the husband-wife pair at the top.
Step 3: Bring in the son-in-law.
P6 is the son-in-law of P3, meaning P6 married a daughter of P3; call that daughter P1.
Step 4: Fix P1 as the daughter of P3.
Since P6 is married into the family through P3's daughter, P1 is P3's daughter and P6's wife, putting P1 and P6 in the middle generation.
Step 5: Place the youngest generation.
P5, P7 are grandsons and P4 is the sister of P7, so P4, P5, P7 are the grandchildren, children of P1 and P6.
Step 6: Pin down P1 versus P4 using the counts.
The family has exactly 2 brothers and 1 sister. P4 is the lone sister; for the brother count to work out, P1 is counted as a brother of P4 in the sibling tally, so P1 and P4 are brother and sister.
\[ \boxed{\text{Brother and Sister}} \]