Question 205795: 2. how many different 4 letter radio station call letters can be made if repeats are allowed and the first letter must be k
a.1000
b.17,576
c.78
d.456,976
Found 2 solutions by stanbon, Targetweek:
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! how many different 4 letter radio station call letters can be made if repeats are allowed and the first letter must be k
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# = 1*26*26*26 = 17576
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Cheers,
Stan H.
a.1000
b.17,576
c.78
d.456,976
Answer by Targetweek(62) (Show Source):
You can put this solution on YOUR website! Well to find possible number of permutations (where order does matter), use the equation...
 Where n is the number of choices (26 in this case) and r is the number chosen at a time (4 in this case)
When plugged in you get 456,976 different call letters
divide that number by 26 and you get 17,576
so the answer is b
This works because...
Ex. A,B,C can be arranged...
A B C
A C B
B A C
B C A
C A B
C B A
there were three choices (or n = 3) and 1/3 of the choices start with A for example, the same applies to the above problem
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