
New Member
Combinations/Permutations where only certain elements in series can vary
Hi all,
I am sorry if this is posted the wrong subforum, but my math knowledge is limited and so I am unsure where else to post.
I am wondering how to calculate the number of possible versions of a series of characters, where only some characters in the series can vary.
5NMB RTTM 8L60 9P7U AJQW 9889
5 
N 
M 
B 
R 
T 
T 
M 
8 
L 
6 
0 
9 
P 
7 
U 
A 
J 
Q 
W 
9 
8 
8 
9 




L 


N 


G 
O 


4 


3 

V 

B 
B 

How many different combinations are possible where only bold characters can vary and they can vary only with the character directly beneath them in the table? Is there a formula for this?
Therefore, the following are possible (characters in red are variations on the original series):
5NMB LTTM 8L60 9P4U AJQW 9889
5NMB RTTM 8L60 9P7U AJQW 9BB9
5NMB LTTN 8LGO 9P4U A3QV 9889
But the following is NOT:
5NMB NTTO 8L60 9P7U ABQB 93V9
I hope this makes sense, and I hope it is ok to post here. I am new to the forum so forgive me if my posting etiquette or anything is offpoint.
I look forward to your responses.

Elite Member
If I understand the problem, you have a sequence of characters. At specific spots in the sequence, a character may be replaced by one other character.
You have 9 spots where an alternative is permitted.
So the number of possible different sequences is [tex]2^9 = 512.[/tex]
Tags for this Thread
Posting Permissions
 You may not post new threads
 You may not post replies
 You may not post attachments
 You may not edit your posts

Forum Rules
Bookmarks