any 4 from 7 is 35, in any order is 35 x 24 ie 840
4!=4x3x2x1=24
There is 1 combination of all ten numbers, 10 combinations of one number and of nine numbers, 45 combinations of two or eight numbers, 120 combinations of three or seven numbers, 210 combinations of four or six numbers and 252 combinations of five numbers. That is 1023 = 210 - 1 in total.
The four numbers that can be used in combinations or differences to make all numbers from 1 to 30 are 1, 2, 4, and 8. These numbers are powers of 2, which allows for the creation of all numbers from 1 to 30 through various combinations and differences. By using these four numbers strategically, one can generate any integer between 1 and 30.
There are 360 of them.
45
7
126 combinations. Remember that the order does not matter.
11
shut up guys
If each number can be used only once then there are just four: 2345, 2346, 2456 and 3456. There are no others because the order of the digits does not matter in combinations.
19
10