SOLUTION: strings of length 9 with elements being a, b or c. How many strings will contain at least 6 b’s
I know the answer is 835 but I am looking for a formula or clarification on how t
Algebra.Com
Question 371103: strings of length 9 with elements being a, b or c. How many strings will contain at least 6 b’s
I know the answer is 835 but I am looking for a formula or clarification on how the answer is derived please. Thank you.
Answer by edjones(8007) (Show Source): You can put this solution on YOUR website!
expand(b+a+c)^9
1 b^9
2*9 b^8...
2*36+72 b^7...
2*84+252*2 b^6...
-------add
835 strings will contain at least 9 b's.
.
Ed
RELATED QUESTIONS
In a strings of length 9 with elements being a, b or c. How many strings will contain at... (answered by robertb)
Consider strings of length 9 with elements being a, b or c. How many
strings will... (answered by stanbon)
In a string of length 9 with elements being a, b or c. How many strings will contain at... (answered by edjones)
Consider strings of length 6 which contain letters only from the set { P,Q,R,S,T} and... (answered by Edwin McCravy)
How many 11-bit strings (that is, bit strings of length 11) are there which:
a)Start... (answered by ikleyn)
How many bit strings of length 4 contain either 3 consecutive 0s or 3 consecutive 1s?... (answered by greenestamps)
consider strings of length 10 which contain only letters from the set{A,E,I,O,U} and... (answered by Edwin McCravy)
How many 12-bit strings (that is, bit strings of length 12) are there which:
have weight (answered by ikleyn)
The letters C,I,R,C,L, and E can be used to form 6-letter strings such as CIRCLE or... (answered by ikleyn)