Difficulty: Hard
Correct Answer: Doctor
Explanation:
Introduction / Context:
This is a classic family plus professions reasoning puzzle combining information about marriages, generations and job titles. You are told that six people A, B, C, D, E and F each have one distinct profession and you must determine the profession of B. Solving this requires careful elimination and construction of a consistent family and profession assignment that satisfies every given condition.
Given Data / Assumptions:
Concept / Approach:
We first assign professions that are explicitly given: D is the Salesman, C is the Lawyer, E is the Engineer and F is the Accountant. That leaves Doctor and Teacher to be assigned to A and B in some combination. Next we use the marriage clues: the Doctor is married to the Lawyer (C), and D is married to the lady Teacher. We also know A is the grandmother of F and C is the daughter-in-law of A, so C is married to A's son, who must therefore be the Doctor. By fitting these pieces together and ensuring there are exactly two married couples, we can deduce that B must be the Doctor.
Step-by-Step Solution:
Step 1: Assign fixed professions: D = Salesman, C = Lawyer, E = Engineer, F = Accountant.Step 2: The remaining professions are Doctor and Teacher, which must belong to A and B in some order.Step 3: The Doctor is married to the Lawyer. Since C is the Lawyer, C is married to the Doctor.Step 4: C is also the daughter-in-law of A, which means C is married to A's son. Therefore, A's son is the Doctor.Step 5: A is the grandmother of F, and F is the son of B. This means B is a child of A (the parent of F).Step 6: For C to be the daughter-in-law of A, C must be married to one of A's children. Since B is a child of A and F is B's son, a consistent and standard solution is that B is the Doctor married to C, the Lawyer.Step 7: D, the Salesman, is married to the lady Teacher. Since Teacher is the only remaining profession, A becomes the Teacher and the spouse of D.Step 8: This assignment satisfies all conditions: two married couples (A–D and B–C), correct professions, F as the Accountant son of B, E as the unmarried Engineer, and A as the grandmother of F.
Verification / Alternative check:
Check all constraints one by one: D is the Salesman and married to the lady Teacher A. B is the Doctor and married to C, the Lawyer, which matches the Doctor is married to the Lawyer. C is the daughter-in-law of A because C is married to A's child B. F is the Accountant son of B and brother of E; E is unmarried and is the Engineer. A is the grandmother of F as B is her child and F is B's son. Every statement is satisfied without contradiction, and there is no need to create a third married couple. If you try to assign Doctor to A and Teacher to B, you cannot keep the number of married couples to two while satisfying all in-law relationships, so that alternative fails.
Why Other Options Are Wrong:
Teacher cannot be B's profession because then A would have to be the Doctor, but C (the Lawyer) must be married to the Doctor and also be A's daughter-in-law. This breaks the grandmother and daughter-in-law structure.Lawyer is already assigned to C, and Salesman is already assigned to D, so B cannot hold either of those professions.None of these is incorrect because Doctor fits perfectly and uniquely.
Common Pitfalls:
Many students forget to enforce the constraint that there are exactly two married couples and accidentally create three couples when distributing professions and in-law relationships. Others overlook that daughter-in-law fixes both the generation and the direction of the relationship. The safest strategy is to assign all known professions first, then use the marriage clues, and finally fit in the grandparent relationship to lock down which child of A is married to C.
Final Answer:
The profession of B is Doctor.
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