Question

Some credit card numbers have special digits. Suppose a card's number must start with 37 followed by a nonzero digit. Then the 13 following digits can be any number from 0 to 9. How many different credit numbers are possible?

Answer 1

The total number of different credit card numbers possible is 900 trillion.

Step-by-step explanation:

To find the number of different credit card numbers that are possible, we need to determine the number of choices for each digit in the number. The first two digits are fixed, as they must be '37'. The third digit must be nonzero, so there are 9 choices (digits 1 through 9). For the remaining 13 digits, there are 10 choices (digits 0 through 9).

Therefore, the total number of different credit card numbers possible is 9 * 10^13, which is 900,000,000,000,000 or 900 trillion.