1. How many ways can you possibly have if you bet on a single number if there are 38 possible number of choices you have?
2. How many winning combinations can you have when you have 12 numbers to choose from out of 38?
I am not sure what you mean by 1.
If you are just betting on one number there are 38 possible outcome if one number is chosen.
For your second one, this is a combination.
taking 12 out of 38.
38!/((12!)(26!))
Do you know what factorial means?
For example: 5! = 5 times 4 times 3 times 2 times 1 = 120