how many 7-digit phone numbers can be formed if the first digit cannot be 0 or 1, and any digit can be repeated

Question

Mathematics

Jaeden Watkins

6 July, 10:21

how many 7-digit phone numbers can be formed if the first digit cannot be 0 or 1, and any digit can be repeated

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Answers (1)

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Kayden Mcintyre · Answer 1

8 * 10⁶

Step-by-step explanation:

The first digit can be any number from 2 to 9. We can select any of the eight digits.

We can select the remaining digits in ten different ways.

Each choice is independent, so we can multiply the choices together.

N = 8 * 10 * 10 * 10 * 10 * 10 * 10

= 8 * 10⁶ possibilities

There are 8 * 10⁶ possible seven-digit phone numbers.