NIMCET 2011 Logical Reasoning Question 74 with Solution

Question 74

Logical Reasoning Puzzles Easy

A, B, C, D, E, F and G are sitting in a line facing East. C is immediate to the right of \( D \) . \( B \) is at one of the extreme ends and has E as his neighbour. G is between E and F . D is sitting third from the south end. There is a family party consisting of two fathers, two mothers, two sons, one father-in-law, one mother-in-law, one daughter-in-law, one grandfather, one grandmother and one grandson. What is the minimum number of persons required so that this is possible?

(A) 5

(B) 6

(C) 7

(D) 8

View Dynamic Solution & Explanation ▼

Correct Solution: Option A

Step-by-step Solution:

Quick Solution & Analysis

This question is a combination of two parts. The first paragraph about the seating arrangement of friends A-G is irrelevant information designed to distract from the actual question.

The real puzzle is in the second part: "There is a family party consisting of...". The goal is to find the smallest number of people required to fill all the listed family roles.

1. Building the Family Structure

The key is to start with the roles that require the most generations: a grandfather, a grandmother, and a grandson. This immediately sets up a three-generation family.

To have a grandfather and a grandson, there must be a father in the middle generation. So we have: Grandfather → Father → Grandson.
For the roles of "two mothers" and "daughter-in-law", the father in the middle generation must be married.

This gives us the smallest possible family structure that could fit all the roles:

  Gen 1: Grandfather <=> Grandmother
             | 
  Gen 2:          Son <=> Son's Wife (Daughter-in-law)
                    | 
  Gen 3:                Grandson

2. Checking All Roles Against the 5-Person Family

This structure consists of exactly 5 people. Let's verify that this group can fulfill all nine required roles:

Grandfather: Yes (1)
Grandmother: Yes (1)
Grandson: Yes (1)
Two Fathers: Yes (The Grandfather and his Son)
Two Mothers: Yes (The Grandmother and her Son's Wife)
Two Sons: Yes (The Son and the Grandson)
Father-in-law: Yes (The Grandfather to his Son's Wife)
Mother-in-law: Yes (The Grandmother to her Son's Wife)
Daughter-in-law: Yes (The Son's Wife)

Since all conditions are met with just 5 people, this is the minimum number required.

Final Answer: The minimum number of persons required is 5.