# Permutations with repeats?

• July 23rd 2009, 10:43 AM
bosoxy
Permutations with repeats?
Hi

I am a little afraid of the rule I just read regarding posting when you know nothing about what you're posting, but hopefully someone will forgive me....

I am trying to calcualte something for work at the moment, but just can't get to the right answer.

Basically I have to calculate how many permutations of 6 individual variables I can have if the "answer" to each is Yes or No, where you can have 0 to 6 Yes's and 0 to 6 No's and all permutations(?) in between. I think permutaiton is correct as the order does matter.

I'm so sorry if this does not make sense. I've tried this based on some research and still not sure if the answer is 60, 64 or something much larger.

Thansk very much!
• July 23rd 2009, 10:52 AM
Plato
Quote:

Originally Posted by bosoxy
Basically I have to calculate how many permutations of 6 individual variables I can have if the "answer" to each is Yes or No, where you can have 0 to 6 Yes's and 0 to 6 No's and all permutations(?) in between.

What you want to know is: "How many strings of Y's or N's of length six are possible?"
The answer is $2^6=64$. We have six positions with two possible entries. Two times itself six times.
• July 23rd 2009, 10:55 AM
bosoxy
Thanks so much - you wrote the question for me and answered it in a way that all of a sudden makes sense!