If the numbers are allowed to repeat, then there are six to the fourth power possible combinations, or 1296. If they are not allowed to repeat then there are only 360 combinations.
how many combinations of 4 numbers are there in 7 numbers
There are: 9C6 = 84 combinations
10 Combinations (if order doesn't matter). 3,628,800 Possiblilities (if order matters).
8C4 = 70
There are 32C3 = 32*31*30/(3*2*1) = 4960 combinations. I do not have the inclination to list them all.
The number of combinations of six numbers that can be made from seven numbers will depend on if you can repeat numbers. In all there are over 2,000 different numbers that can be made.
45
how many combinations of 4 numbers are there in 7 numbers
6
6
There are: 9C6 = 84 combinations
Twenty factorial which is denoted by "20!". 20! = 1x2x3x4x5x6x7x8x...x19x20
they are 21C2 combinations
36^36 (36 * 36 * 36 * 36 * 36 *...)
24
10
8C6 = 28