Possible Permutations & Combinations

In summary, the conversation discusses the different cases of combinations in three registers (A, B, and C) and how they follow a linear path. The question is how many combinations can be achieved by exploiting all permutations/combinations in Case 1, Case 2, and Case 3. The formula used to deduce the answer involves nested loops, which can be written out as an equation.
  • #1
hello_math
5
0
Hi all

I am new , and wanted to ask the following. I do not know if this is the right section but here goes:

I have three registers , say A , B and C

Case 1:A will always have 3 combinations 1,2,3

1 has further subsections 1_1,1_2,1_3,1_4,1_5
2 has further subsections 2_1,2_2,2_3
3 has further subsections 3_1,3_2,3_3,3_4,3_5,3_6

A will always have to go through 1, 2 ,3 and will have 1 path of any subsection

Example , a possible combination

A--(will always traverse)1--(and will end with one of the subs)1_1
|
|
|--(will always traverse)2--(and will end with one of the subs)2_2
|
|
|--(will always traverse)3--(and will end with one of the subs)3_4


another example

A--1--1_5
|
|
|--2--2_1
|
|
|--3--3_1

++++++++++++++++++++++++++++++++++++++++++++++++++++

the same holds good for B too

Case 2:B will always have 3 combinations 4,5,6

4 has further subsections 4_1,4_2,4_3,4_4,4_5
5 has further subsections 5_1,5_2,5_3
6 has further subsections 6_1,6_2,6_3,6_4,6_5,6_6

(Just like A) B will always have to go through 4, 5 ,6 and will have 1 path of any subsection

Example , a possible combination

B--4--4_3
|
|
|--5--5_3
|
|
|--6--6_4


+++++++++++++++++++++++++++++++++++++++++++++++++++

and Finally , there's a combination of (A+B)

Case 3:
- where A will again take the same path/s as mentioned for A above

- where B will again take the same path/s as mentioned for B above

Example , a possible combination

A--1--1_5 B--4--4_3
| |
| |
|--2--2_1 And |--5--5_3
| |
| |
|--3--3_1 |--6--6_4

if the above did not come all right here in the forum(my dabbings with the notepad , so here's the picture I want to show for Case 3:
http://i856.photobucket.com/albums/ab124/Hello_123_01/13-2.jpg

Here's a hand sketch of what I have been trying to explain above , for A and B respectively.

http://i856.photobucket.com/albums/ab124/Hello_123_01/13-1.jpg
Case 3 is as mentioned a (case1 +Case 2)



My question is: How many combinations do I have , till I have exploited all permutations/combinations ? so all combinations/permutations that could be covered by Case1 , Case 2 and Case 3
and what formula did you use to deduce it ?
My math is outdated now , but the formula will always help to identify this issue I am facing .


Thanks for any help here


*PS: I have to mention, that the path is always linear. so for example:
1 Path = B + 4+ 4_1 | B + 5+ 5_1 | B+6+6_1 = Linear path , Right Path
next combination = B + 4+ 4_1 | B + 5+ 5_2 | B+6+6_1
next combination = B + 4+ 4_1 | B + 5+ 5_3 | B+6+6_1
next combination = B + 4+ 4_2 | B + 5+ 5_1| B+6+6_1


and so on...

Path = B + 4+ 4_1 | B + 5+ 5_1/5_2/5_3 | B+6+6_1/6_2/6_3 = wrong , not this way (no simultaneous or multiple paths)

I hope I was able to explain myself
 
Last edited by a moderator:
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  • #2
Your links are broken, but I think I understand what you mean.
Suppose you were to design a computer program to compute the number of combinations. (I am not suggesting that you actually do that, although it wouldn't be very hard, just that you think about how you would design a computer program to compute the answer to your problem.) If I understand what you are trying to do, I think you could design the program as a set of nested loops. If you can do that, then I think you can write out the equation for the answer.
 
  • #3
Thanks you for sharing.
 

1. What is the difference between permutations and combinations?

Permutations and combinations are both ways to count the number of possible arrangements of a set of objects. The main difference between them is that permutations take into account the order of the objects, while combinations do not. This means that in permutations, the order of the objects matters, while in combinations, it does not.

2. How do I calculate the number of possible permutations?

The number of possible permutations can be calculated using the formula nPr = n! / (n-r)!, where n is the total number of objects and r is the number of objects being chosen. This formula is used when order matters, such as arranging a sequence of letters or numbers.

3. How do I calculate the number of possible combinations?

The number of possible combinations can be calculated using the formula nCr = n! / (r!(n-r)!), where n is the total number of objects and r is the number of objects being chosen. This formula is used when order does not matter, such as selecting a group of people from a larger group.

4. Can I have repetitions in permutations and combinations?

Yes, repetitions are allowed in both permutations and combinations. This means that the same object can be used more than once in the arrangement or selection. However, the number of repetitions must be specified in the formula used to calculate permutations or combinations.

5. How can I use permutations and combinations in real life?

Permutations and combinations are used in various fields such as mathematics, statistics, and computer science. In real life, they can be used to calculate the number of possible outcomes in a game, to arrange a set of books on a shelf, or to select a team from a group of players. They can also be used in more complex problems, such as analyzing data in genetics or predicting outcomes in economics.

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