How many 7-digit phone numbers are possible if the number Cannot start with 0 and the digits Cannot repeat?

The simple answer is 9999999–(0)999999, which is 9000000.

How many ways can 7-digit numbers can be formed if repetition is not allowed?

For the third place we have 8 options to choose from 0 to 9 excluding the digits we already placed on first and second positions. Hence the answer appears. Also there will be 6∗6∗5∗4∗3∗2∗1=4320 seven digit numbers having the digits 0,1,2,3,4,5,6 giving minimum sum as 21.

How many combinations can you make with 7 digits?

Assuming repetition is allowed, you can have 7-digit numbers from 1,000,000 to 9,999,999 which is a total of 9,000,000 7-digit numbers. These are all the possible 7-digit numbers. In general, there are 9 × 10^(n-1) possible n-digit numbers.

How many seven digit numbers are available given restrictions that the first three digits can not be 911 or 411 the first digit can not be a 1 or 0?

= 8,000,000. Therefore, according to the condition that the first digit cannot be either 1 or 0, we can have 8,000,000 possible ways of creating a seven-digit area code. Now, according to the other condition which states that the first three-digits cannot have the numbers 911 or 411.

What is a 7 digit phone number?

Unsourced material may be challenged and removed. Seven-digit dialing is a telephone dialing procedure customary in the territories of the North American Numbering Plan, for dialing telephone numbers in the local calling area. The procedure is also sometimes known as local format or network format.

How many seven-digit numbers can be made from the digits 1 to 7 if repetition is allowed?

The numbers beginning with 0 won’t be 7 digit numbers, they would be 6 digit numbers. No. of such numbers are: 6!/(3!

How many phone number combinations are possible?

Each area code has 792 prefixes or “NXX” codes. Each NXX has 10,000 possible numbers. Therefore, theoretically, there are 7,920,000 telephone numbers per area code.

How many 3 digit telephone area codes are possible if each digit can be from 0 9?

For the 3-digit area code, the first digit can be any digit from 2 through 9, and each of the two digits that follow can be any digit from 0 through 9. That’s a total of 8 × 10 × 10 = 800 different combinations. The same restrictions apply to the 3-digit exchange code.