Question

Indiana now has 8 different area codes. How many different phone numbers are available within Indiana if the numbers can repeat? Remember that phone numbers have an area code followed by 7 digits.

Answer 1

Well, this could turn out to be a simple permutation problem: you have ten number choices (0-9) for each digit of a phone number and repetitions are allowed. Technically, there could be as many as \begin{align*}10^{10} = 10,000,000,000\end{align*}, or 10 billion possible phone numbers.

Explanation:

:D