21
How many digits are in each combination ? ? -- If one, then there are three combinations: {5}, {6}, and {7) . -- If two, then there are three combinations: {5, 6}, (5, 7), and {6, 7}. -- If three, then there is only one combination: {5, 6, 7}
7C3 = 7*6*5/(3*2*1) = 35 combinations.7C3 = 7*6*5/(3*2*1) = 35 combinations.7C3 = 7*6*5/(3*2*1) = 35 combinations.7C3 = 7*6*5/(3*2*1) = 35 combinations.
There is 1 combinations with 7 numbers in them,7 combinations with 1 or 6 numbers in them,21 combinations with 2 or 5 numbers in them,35 combinations with 3 or 4 numbers in them.Notionally, there is also one combination with no numbers in it.In all then, there are 128 ( = 27) combinations.There is 1 combinations with 7 numbers in them,7 combinations with 1 or 6 numbers in them,21 combinations with 2 or 5 numbers in them,35 combinations with 3 or 4 numbers in them.Notionally, there is also one combination with no numbers in it.In all then, there are 128 ( = 27) combinations.There is 1 combinations with 7 numbers in them,7 combinations with 1 or 6 numbers in them,21 combinations with 2 or 5 numbers in them,35 combinations with 3 or 4 numbers in them.Notionally, there is also one combination with no numbers in it.In all then, there are 128 ( = 27) combinations.There is 1 combinations with 7 numbers in them,7 combinations with 1 or 6 numbers in them,21 combinations with 2 or 5 numbers in them,35 combinations with 3 or 4 numbers in them.Notionally, there is also one combination with no numbers in it.In all then, there are 128 ( = 27) combinations.
the first digit can be any of the seven numbers, the second can be any of the remaining 6 etc so there are 7 x 6 x 5 x 4 x 3 x 2 x 1 combinations. This is known as "factorial 7" and is normally written "7!" and is 5040.
2 to the 7th power = 128 * * * * * No. That is the total number of combinations, consisting of any number of elements. The number of 2 number combinations is 7*6/2 = 21
fifty * * * * * What sort of rubbish answer is that? There are 10C5 = 10*9*8*7*6/(5*4*3*2*1) = 252 combinations.
Assuming the digits cannot be repeated, there are 7 combinations with 1 digit, 21 combinations with 2 digits, 35 combinations with 3 digits, 35 combinations with 4 digits, 21 combinations with 5 digits, 7 combinations with 6 digits and 1 combinations with 7 digits. That makes a total of 2^7 - 1 = 127: too many for me to list. If digits can be repeated, there are infinitely many combinations.
If you don't repeat them, you can get up to six different combinations.
It depends on the sizes of the combinations. For example, there is only one combination of 7 things out of 7, but there are 21 combinations of two items.
7*3*4 = 84 combinations.
You can make 5 combinations of 1 number, 10 combinations of 2 numbers, 10 combinations of 3 numbers, 5 combinations of 4 numbers, and 1 combinations of 5 number. 31 in all.
Not repeating, it is 7*6*5*4 which is 840 ways ---- There are 7 choices for each of four digits, right? 74 = 2401