SOLUTION: How many different 4-letter radio call letters can be made using the 26 capital letters of the English alphabet (Examples: WJBR, KDKA, WSTW) if the first letter must be K or W and

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Question 508959: How many different 4-letter radio call letters can be made using the 26 capital letters of the English alphabet (Examples: WJBR, KDKA, WSTW) if the first letter must be K or W and no letter may be repeated.
Found 2 solutions by oberobic, josmiceli:
Answer by oberobic(2304) (Show Source):
You can put this solution on YOUR website!
The first letter has 2 possibilities: K and W.
The second letter has 24 possibilities given you cannot reuse K or W.
Once you take that letter, then the third letter has only 23 possibilities.
After you pick the third letter, then you only 22 choices for the last letter.
.
2*24*23*22 = 24288
.
BUT in your example you showed WSTW, which suggests the K and the W can be repeated as one of the other three letters. In turn, that means your total patterns are:
.
2*26*25*24 = 31200
.
Done.

Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website!
There are possible choices for the 1st letter
Repetitions are not allowed, so
there are choices for the 2nd letter
for the 3rd letter
for the 4th letter
Multiply possible choices to get all
possible combinations of letters

There are 27600 possible 4-letter radio call signs