"In the original plan for area codes in 1945, the first digit could be any number from 2 through 9, the second digit was either 0 or 1, and the third digit could be any number except 0. With this plan, how many different area codes are possible?"
I'm pretty sure I have to sure I have to use exponents to figure this one out, but I'm not sure how. Help?|||Multiply the number of possible digits in the first place by the number in the second place by the number in the third place.
# of digits 2 - 9: 8
# of digits 0,1: 2
# of digits 1-9: 9
8*2*9 = 144
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