A school principal and his wife, along with three other teachers, are to be seated in a row. The principal and his wife must sit next to each other. Find the number of ways this can be done.

Discrete MathematicsPermutationsCombinatoricsArrangementsConstraints
2025/3/27

1. Problem Description

A school principal and his wife, along with three other teachers, are to be seated in a row. The principal and his wife must sit next to each other. Find the number of ways this can be done.

2. Solution Steps

There are a total of 5 people to be seated. The principal and his wife must sit together. We can treat the principal and his wife as a single unit.
First, consider the principal and his wife as one entity. So now we have 4 entities to arrange: (principal and wife), teacher 1, teacher 2, teacher

3. The number of ways to arrange these 4 entities in a row is $4! = 4 \times 3 \times 2 \times 1 = 24$.

Next, the principal and his wife can switch positions within their unit. So there are 2 possible arrangements for the principal and wife: (principal, wife) or (wife, principal). Therefore, there are 2 ways to arrange the principal and wife within their unit.
To get the total number of ways to arrange the 5 people with the given condition, we multiply the number of arrangements of the 4 entities by the number of arrangements within the principal-wife unit:
24×2=4824 \times 2 = 48.

3. Final Answer

The number of ways this can be done is 48.

Related problems in "Discrete Mathematics"

Question 11: Given sets $A = \{a, b, c\}$, $B = \{a, b, c, d, e\}$, and $C = \{a, b, c, d, e, f\}$, ...

Set TheoryUnionIntersectionModeMedianStatistics
2025/6/5

The given Venn diagram shows the number of elements that are multiples of 2 and multiples of 3. The ...

Venn DiagramsSet TheoryDivisibilityCounting
2025/6/4

The problem asks for the truth table for negation. Negation is a unary operation on a logical value,...

LogicTruth TablesNegation
2025/6/4

The problem is to complete the truth table for the logical expression $\neg P \wedge Q$. The table p...

Boolean AlgebraLogicTruth TablesPropositional Logic
2025/6/4

Given two sets $A = \{apple, banana, cherry\}$ and $B = \{red, yellow\}$, find the Cartesian product...

Set TheoryCartesian Product
2025/6/4

The problem asks us to draw a Venn diagram representing two sets, A and B. Set A contains the first ...

Set TheoryVenn DiagramsIntersection of SetsEven NumbersMultiples
2025/6/4

The problem asks when the logical implication $p \rightarrow q$ is considered true. We are given 5 o...

LogicTruth TablesImplication
2025/6/4

We are given that there are 4 boys and 5 girls standing in a line. We are asked to find: a) The tota...

PermutationsCombinationsCounting Principles
2025/6/4

The problem asks about the number of ways to arrange 4 math books, 3 physics books, and 2 chemistry ...

CombinatoricsPermutationsArrangementsFactorials
2025/6/4

We are given three sets $M$, $N$, and $\mu$. $M$ contains integers $x$ such that $2 \le x \le 6$, $N...

Set TheorySet OperationsComplementIntersection
2025/6/3