A typical Social Security number is 555-47-5593. How many Social Security numbers are possible if the first two digits cannot be 3?

Question

A typical Social Security number is 555-47-5593. How many Social Security numbers are possible if the first two digits cannot be 3?​

Quizplus · Accepted Answer

There are 8 possible digits for the first digit (0-2, 4-9) and 9 possible digits for the second digit (0-9). There are 10 possible digits for each of the remaining 7 digits. So, the total number of possible Social Security numbers is 8 * 9 * 10 * 10 * 10 * 10 * 10 = 810,000,000.

A Typical Social Security Number Is 555-47-5593