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.
You could make 10*10*10*26*26*26 combinations, or 17576000 combinations.
Their is 25 combinations
Two . . . . . 38 and 83.
Only one.
13 combinations of 3
∞ \ Infinite
Assuming that the six numbers are different, the answer is 15.
14 * * * * * Wrong! There are 15. 4 combinations of 1 number, 6 combinations of 2 number, 4 combinations of 3 numbers, and 1 combination of 4 numbers.
There are: 9C6 = 84 combinations
35
26 = 64 combinations, including the null combination - which contains no numbers.