A telephone number in a single area code is composed of 7 digits from 0 to 9. Determine the amount of p numbers available in the 856 area code if the first digit cannot be 0 or 1. 8,000,000 604,8 oo 10,000,000 483,840

Here's how to calculate the number of available phone numbers:<br /><br />* **Digits 2-7:** Each of these digits can be any number from 0 to 9, giving 10 possibilities for each digit.<br />* **Digit 1:** The first digit can be any number from 2 to 9, giving 8 possibilities.<br /><br />Therefore, the total number of available phone numbers is 8 * 10 * 10 * 10 * 10 * 10 * 10 = 8,000,000<br /><br />So the correct answer is $\boxed{8,000,000}$<br />