A telephone number in the US or Canada is a ten-digit number whose first two digits cannot be a 0 or 1. How many telephone numbers are possible?How many possible phone numbers?
Actually this is wrong; a typical US ten-digit phone number begins with 1. But going strictly with the problem here...
There are 8 possible digits for the first, 8 possible digits for the second, and 10 possible digits for the remaining eight. So that means 8*8 * 10^8 = 6.4 * 10^9 possible combinationsHow many possible phone numbers?
8 x 10^9
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