# Thread: Ways to differ from a sequence by n

1. ## Ways to differ from a sequence by n

Say I have a set like a,b,c,d,e,f,g,h,i,j
And, I pick five like abcde

how many ways can I pick 5 such that it differs from the original by n?

For example by two like bacde, or fgcde? It is driving me nuts since it changes based on the use of one of the original characters. In other words, there are five ways to have the first two characters differ that start with 'j,' but 6 ways to have the first two characters differ that start with 'b.'

2. ## Re: Ways to differ from a sequence by n

What do you mean by "differ by no"? What is "n"? What is "n" in the examples you give?

3. ## Re: Ways to differ from a sequence by n

Originally Posted by HallsofIvy
What do you mean by "differ by no"? What is "n"? What is "n" in the examples you give?
In the examples, n=2

4. ## Re: Ways to differ from a sequence by n

Originally Posted by HallsofIvy
What do you mean by "differ by no"? What is "n"? What is "n" in the examples you give?
In other words, two(ie n) of the characters are different than the original sequence.