9+8+2=19 9+7+3=19 9+6+4=19 There are a limited number of possibilities but there are absolutely loads
Number of 7 digit combinations out of the 10 one-digit numbers = 120.
27
There are 15180 combinations.
There are 5,461,512 such combinations.
There are 840 4-digit combinations without repeating any digit in the combinations.
There are 210 4 digit combinations and 5040 different 4 digit codes.
There are 9C3 = 84 combinations.
64
14
There are 5,040 combinations.
There are 1,000,000 possible 6-digit combinations. This is calculated by considering that each digit can range from 0 to 9 (10 possible values), and since there are 6 digits, the total combinations are (10^6 = 1,000,000).
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 5-digit combinations.