Question

Area codes are made up of three digit numbers
a. If all numbers can be used for each digit, how many area codes are possible?

Answer 1

There are 10 digits that can be used for each digit; for a problem like this, where digits can be repeated (ex. 333), you take your base of 10, how many numbers possible for each digit, and you raise it to how many places there are (3)\[10^3=1000\]