Math Problem Statement
Solution
This image contains a problem written in Japanese about arranging five people (A, B, C, D, and E) in a row. Here is the translation and explanation of the three questions in the image:
- (1) How many ways can the arrangement be made if A is at one end?
- (2) How many ways can the arrangement be made if B and C are next to each other?
- (3) How many ways can the arrangement be made if B and C are not next to each other?
Solutions:
(1) A is at one end:
If A must be at one end (either the first or the last position), then we fix A in one of the two end positions. The remaining four people (B, C, D, E) can be arranged in the remaining 4 positions. The number of ways to arrange 4 people is . Since A can be at either end (two options), the total number of arrangements is:
(2) B and C are next to each other:
We can treat B and C as a single block (BC or CB), so we are now arranging 4 blocks: (BC), A, D, E. The number of ways to arrange these 4 blocks is . Since B and C can switch places within the block (BC or CB), we have 2 ways to arrange them within the block. Therefore, the total number of ways is:
(3) B and C are not next to each other:
The total number of arrangements without restrictions is . From this, we subtract the number of ways in which B and C are next to each other (calculated in part (2), which is 48). Therefore, the number of ways in which B and C are not next to each other is:
Final Answers:
Would you like any further details or clarification?
Related Questions:
- How many ways can the five people be arranged without any restrictions?
- If A must be in the center, how many different arrangements are possible?
- How many ways can the arrangement be made if D and E must be next to each other?
- If A and B cannot be next to each other, how many different arrangements are possible?
- How many ways can the arrangement be made if B and C must be at the ends?
Tip:
When solving arrangement problems involving "next to each other" conditions, try grouping the elements into a single block for simplicity.
Ask a new question for Free
By Image
Drop file here or Click Here to upload
Math Problem Analysis
Mathematical Concepts
Permutations
Combinatorics
Factorials
Formulas
Number of ways to arrange n items: n!
Restricted arrangement (specific positions): 4! for 4 items
Theorems
Basic permutation and combination principles
Suitable Grade Level
Grades 9-12
Related Recommendation
Counting Linear Arrangements with A, B, and C
Calculate Number of Arrangements with Specific Seating Conditions
Counting Permutations with Order Constraints for 8 Individuals
Arranging 5 People from 10 with Bride and Groom in Wedding Photos
Arranging People in a Row with Restrictions: Bride and Groom Inclusion