Question

How many 7-digit phone numbers are possible, assuming that the first digit can't be a 0 or a 1?"

Answer 1

8000000 numbers

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First, consider the restrictions for the first digit.

Since the first digit cannot be 0 or 1, we have 8 options, (2-9) for the first digit.

For each of the remaining 6 digits, we have 10 options (0-9).

To find the total number of phone numbers, we multiply the number of options for each digit together:

• 8 x 10 x 10 x 10 x 10 x 10 x 10 = 8000000