It is: 6C4 = 15
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I disagree with the first answer.
Each of the four digits can be chosen in 6 ways: 6 x 6 x 6 x 6 = 64 = 1296
Assuming that repeated numbers are allowed, the number of possible combinations is given by 40 * 40 * 40 = 64000.If repeated numbers are not allowed, the number of possible combinations is given by 40 * 39 * 38 = 59280.
The number of four-digit combinations is 10,000 .Stick a '3' before each of them, and you have all the possible 5-digit combinations that start with 3.There are 10,000 of them. They run from 30,000 to 39,999 .
9x8x7x6x5x4x3x2x1 or 9! which equals 362880 possible combinations if no digits are repeated
Assuming the digits are not repeated, there are four combinations:123, 124, 134 and 234.
3897
Assuming that repeated numbers are allowed, the number of possible combinations is given by 40 * 40 * 40 = 64000.If repeated numbers are not allowed, the number of possible combinations is given by 40 * 39 * 38 = 59280.
The number of four-digit combinations is 10,000 .Stick a '3' before each of them, and you have all the possible 5-digit combinations that start with 3.There are 10,000 of them. They run from 30,000 to 39,999 .
9x8x7x6x5x4x3x2x1 or 9! which equals 362880 possible combinations if no digits are repeated
Number of 7 digit combinations out of the 10 one-digit numbers = 120.
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.
This question needs clarificatioh. There are 4 one digit number combinations, 16 two digit combinations, ... 4 raised to the n power for n digit combinations.
Assuming the digits are not repeated, there are four combinations:123, 124, 134 and 234.
3897
If no digit is repeated, then there are (9 x 8 x 7)/(3 x 2) = 84 combinations.
9
It is possible to create a 3-digit number, without repeated digits so the probability is 1.
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 combinationsThree 1-digit numbers and one 2-digit number: 1344 combinationsOne 1-digit numbers and two 2-digit numbers: 1080 combinationsThat 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 reduce the number of combinations.