Help for combinatorial question?

  • Thread starter Thread starter erogol
  • Start date Start date
erogol
Messages
14
Reaction score
0
a "codeword" from the alphabet A={0,1,2,3) is said to be legitimate if it contains even number of zeros. Thus for instance the codeword 31020 is legitimated and 0002 is not. How many n - letter codewords are legitimated ?
 
Physics news on Phys.org
erogol said:
a "codeword" from the alphabet A={0,1,2,3) is said to be legitimate if it contains even number of zeros. Thus for instance the codeword 31020 is legitimated and 0002 is not. How many n - letter codewords are legitimated ?

Hi erogol! :wink:

Show us what you've tried, and where you're stuck, and then we'll know how to help! :smile:
 
i have no sense to solve it i just know answer is 2^(2n-1) + 2^n -1
 
erogol said:
i have no sense to solve it i just know answer is 2^(2n-1) + 2^n -1

ok, start by making a sum over all possible (even) numbers of 0s …

the total number of legitimated words is ∑ what ? :smile:
 
So you are not even going to try?
 
HallsofIvy said:
So you are not even going to try?

Are you talking to me? :biggrin:
 

Thread 'Here's a Statistics problem for game of Polo (or Hockey if you like)'

Namaste & G'day Postulate: A strongly-knit team wins on average over a less knit one Fundamentals: - Two teams face off with 4 players each - A polo team consists of players that each have assigned to them a measure of their ability (called a "Handicap" - 10 is highest, -2 lowest) I attempted to measure close-knitness of a team in terms of standard deviation (SD) of handicaps of the players. Failure: It turns out that, more often than, a team with a higher SD wins. In my language, that...
View full post »

Thread 'Roulette wheel physics and probability'

Hi all, I've been a roulette player for more than 10 years (although I took time off here and there) and it's only now that I'm trying to understand the physics of the game. Basically my strategy in roulette is to divide the wheel roughly into two halves (let's call them A and B). My theory is that in roulette there will invariably be variance. In other words, if A comes up 5 times in a row, B will be due to come up soon. However I have been proven wrong many times, and I have seen some...
View full post »

Similar threads

MHB What Is an Encoding Matrix in Coding Theory?
Replies
6
Views
2K
Where Does 10^{n-1} Come From in the Recurrence Relation Example?
Replies
6
Views
4K
MHB A simple (?) combinatorial problem
Replies
2
Views
2K
Frame Synchronisation via Modified Approach to Bit Insertion
Replies
2
Views
2K
MDS/cyclic code, binary string question
Replies
5
Views
3K
MHB Graph Grammer Function For Two Exotic Graphs Question please.
Replies
4
Views
2K
Counting Quadruples of Integers: A Combinatorial Problem
Replies
3
Views
2K
I Making Sense of Notation Confusion in Statistical Digital Signal Processing
Replies
6
Views
2K
Proof that if the alphabet set is at most countable, then strings cnt
Replies
4
Views
3K
MHB Sum of first m terms of a combinatorial number
Replies
2
Views
2K

Hot Threads

Recent Insights

Back
Top