posted by student .
Is this correct?
consider determining how many possible phone numbers are in an area code (repeated numbers allowed)
Is this a combination, a permutation, or neither?
I think it would be a combination wouldn't it?
Since there are ten number possibilities in each of the three spaces of the area code and repeats are allowed, there are 10^3 (1000) possible permutations.
To distinguish combinations from permutations, see the following sources:
I hope this helps. Thanks for asking.