SOLUTION: The call letters of a radio station must have 4 letters. The first letter must be a K or a W. How many different station call letters can be made if repetitions are not allowed?

Question 128730This question is from textbook Statistics
: The call letters of a radio station must have 4 letters. The first letter must be a K or a W. How many different station call letters can be made if repetitions are not allowed? And if repetitions are allowed?
I'm not sure how to set this up, could you please help.This question is from textbook Statistics

Answer by stanbon(48569) (Show Source):
You can put this solution on YOUR website!
The call letters of a radio station must have 4 letters. The first letter must be a K or a W.
How many different station call letters can be made if repetitions are not allowed?
# of ways to pick the 1st letter: 2 ways
# of ways to pick the 2nd letter: 25
# of ways to pick the 3rd letter: 24
# of ways to pick the 4th letter: 23
---------
Total # of ways: 2*25*24*23 = 27600
=========================================
And if repetitions are allowed?
# of ways to pick the 1st leter: 2 ways
# of ways to pick each of the other letters: 26
---------
Total # of ways = 2*26^3 = 35152
===============
Cheers,
Stan H.