# How many different 9 digit combination can be made using numbers one through nine?

9^9 = 387420489 different digit combinations.

### How many 10 digit phone numbers are possible?

Without restrictions, it was would numbers 000-000-0000 through 999-999-9999. So that would be 9,999,999,999 + 1 = 10 billion different 10-digit phone numbers. Ex: If there existed single digit phone numbers, there would be 10, because the digits are 0 through 9. If there existed only double digit phone numbers, then it would be 00 through 99 which would be 100 total two-digit numbers. Therefore the total possible combinations for an X digit phone number…

### What are some 5-digit numbers that are divisible by 4 and 9?

Any multiple of 36 will do. Multiply 36 by different numbers, until you get a 5-digit number. Any multiple of 36 will do. Multiply 36 by different numbers, until you get a 5-digit number. Any multiple of 36 will do. Multiply 36 by different numbers, until you get a 5-digit number. Any multiple of 36 will do. Multiply 36 by different numbers, until you get a 5-digit number.

### How many six digit numbers can be formed using the digits 0123456789 Example equals 123456 or 098765?

The number of six digit numbers that you can make from ten different digits if repetitions of same digit on the six digit number is allowed is 1 000 000 numbers (including number 000 000). If no repetitions of the the same digit are allowed then you have: 10P6 = 10!/(10-6)! = 151 200 different six digit numbers (six digit permutations form 10 different digits).

### How many 4-digit numbers can be formed by the digits 2 4 6?

81 As there are no limits stated then you can have a number comprising a repeated single digit (such as 2222), two pairs of numbers (e.g. 2244) or three different numbers (such as 2462). The first digit can be one of any of the 3 numbers. The second digit can be one of any of the three numbers, as can the third digit and also the fourth. Then you can have 3 x 3 x…

### How many three digit numbers with distinct digits?

1000 there aren't even 1000 three-digit numbers... There are the digits 1 through 9 for the first digit. Then, we have 0 through 9 for the second digit - excluding the first digit. For the third digit, we have 0 through 9, excluding the two previous digits for a total of 9*9*8 = 81*8 = 648 three digit numbers with distinct digits. EDIT- ... to be a little more specific, if your talking about a…

### How many 5 digit combinations for numbers 1- 25?

There are 9 1-digit numbers and 16-2 digit numbers. So a 5 digit combination is obtained as: Five 1-digit numbers and no 2-digit numbers: 126 combinations Three 1-digit numbers and one 2-digit number: 1344 combinations One 1-digit numbers and two 2-digit numbers: 1080 combinations That makes a total of 2550 combinations. This scheme does not differentiate between {13, 24, 5} and {1, 2, 3, 4, 5}. Adjusting for that would complicate the calculation considerably and…

### How many different three digit numbers can you form using the digits 1 2 3 5 6 7 and 9 without repetition?

There are seven possible digits for the first digit and 6 digits for the second (minus one digit for the digit used as the first digit) and 5 options for the last digit (minus one again for the second digit) and then you just multiply them all together to get a total possible combination of 210 numbers that are possible.

### What is a 4 digit perfect square and perfect cube?

I am pretty sure you can figure this out on your own. Raise different numbers to the square, until you get a 4-digit result. Similary, calculate the cube of different numbers, until you get a 4-digit number. If you want the SAME number to be both a perfect square and a perfect cube, then it must be a power of 6. In that case, just experiment raising different numbers to the sixth power, until you…

### How many 5 digit combos in 30 numbers?

The answer will depend on how many digits there are in each of the 30 numbers. If the 30 numbers are all 6-digit numbers then the answer is NONE! If the 30 numbers are the first 30 counting numbers then there are 126 combinations of five 1-digit numbers, 1764 combinations of three 1-digit numbers and one 2-digit number, and 1710 combinations of one 1-digit number and two 2-digit numbers. That makes a total of 3600…

### How many different telephone numbers can be formed from a seven-digit number if the first digit cannot be zero?

Answer is 9 million telephone numbers: from 100-0000 to 999-9999. A 7-digit phone number is no different than a 7-digit number. Each digit can be unique. A 7-digit number can have 10 million combinations (from 0000000 to 9999999). The problem says to exclude all phone numbers starting with a zero (as the first digit). This leaves out 1 million numbers (from 000-0000 to 099-9999). Note: This does not look at what the phone companies consider…