There are 33C6 = 33*32*31*30*29*28/(6*5*4*3*2*1) = 1,107,568 combinations.
36
There are 35C4 = 35*34*33*32/(4*3*2*1) = 52,360 combinations.
Assuming there is no repetition, you want the number of groups of 4 numbers, and the order doesn't matter: this is calculated as 33 over 4; which is the same as (33 x 32 x 31 x 30) / (1 x 2 x 3 x 4)
9
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.
There are 32C3 = 32*31*30/(3*2*1) = 4960 combinations. I do not have the inclination to list them all.
8C3 = 56 of them
There are 23C3 = 23!/(20!*3!) = 23*22*21/(3*2*1) = 1,771 combinations.
If the numbers can be repeated and the numbers are 0-9 then there are 1000 different combinations.
( 36! )/( 32! ) ( 4! ) = (36 x 35 x 34 x 33)/(4 x 3 x 2) = 58,905
There are: 10C3 = 120