8. A palindrome is a string of characters that reads the same forward and backward, such as "BoB" or "d1N1d". Leave formula written out

(a) There are 238,328 different 5-character words (using capitals, lower-case letters, and/or digits 0 - 9) that are palindromes. Show how to get this number. Include a formula and briefly explain how you counted.

(b) How many 6-character words are palindromes (using capitals, lower-case letters, and/or digits 0 - 9)? Include a formula and briefly explain how you counted.

(c) There are 3844 5-character palindromes that begin with "A". There are also 3844 5-letter palindromes that begin with "B". How many 5-character palindromes begin with "A" or "B"? Show how to use the given information - do not create a formula.

(d) There are 3844 5-character palindromes that begin with "X" (and the second letter is anything). There are also 3844 5-letter palindromes whose second letter is "Y" (and the first letter is anything). How many 5-character palindromes begin with "X" or have second letter "Y", or both? Answer using the Principle of Inclusion and Exclusion.