SOLUTION: How many different 7-letter words can be made A. if the first letter must be A, X or T and no letter may be repeated? B. if repeats are allowed (but the first letter is A, X

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Question 993972: How many different 7-letter words can be made
A. if the first letter must be A, X or T and no letter may be repeated?
B. if repeats are allowed (but the first letter is A, X or T)?
C. How many of the 7-letter words (starting with A, X or T) with no repeats end in S?

Found 2 solutions by stanbon, solver91311:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
How many different 7-letter words can be made
A. if the first letter must be A, X or T and no letter may be repeated?
Ans: 3*25*24*23*..*20
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B. if repeats are allowed (but the first letter is A, X or T)?
Ans: 3*26^6
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C. How many of the 7-letter words (starting with A, X or T) with no repeats end in S?
Ans: 3*25*24*..*21*1
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Cheers,
Stan H.
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Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


A. 3 ways to choose the first letter, then 25 ways to choose the second letter, then 24 ways to choose the third letter, and so on. So:



Of course, you have to use the mathematician's definition of a seven-letter word which is just a group of seven letters that do not necessarily have meaning as a word in any particular language. You must also assume though the problem did not specify, that the available letters come from the standard 26 character English alphabet.

John

My calculator said it, I believe it, that settles it