![]() |
|
#1
|
|||
|
|||
![]()
You have three letters 26^3 combinations
how many palindromes are there in the 17,576 combinations |
#2
|
|||
|
|||
![]()
wouldn't it be 26^2?
|
#3
|
|||
|
|||
![]()
I thought it would be 26*25 because the first pick can be any letter, the second letter can be anything except the first pick (25/26) and the third letter can only be the same as the first (1/26).
(25/26)*(1/26) = 27.04 (26^3)/ 27.04 = 650 is there something i'm missing? |
#4
|
|||
|
|||
![]()
Suppose the middle letter is an A . Then the first and third letters may be any of {A,B,C,...Z} . There are 26 letters to choose . However the middle letter may be any of the 26 letters so it should be 26*26 = 676 .
|
#5
|
|||
|
|||
![]()
[ QUOTE ]
Suppose the middle letter is an A . Then the first and third letters may be any of {A,B,C,...Z} . There are 26 letters to choose . However the middle letter may be any of the 26 letters so it should be 26*26 = 676 . [/ QUOTE ] If the middle letter is A then the 1st and 3rd can be anything except A so there are 25 choices for the other letters. |
#6
|
|||
|
|||
![]()
AAA isn't a palindrome?
|
![]() |
|
|