(I am not sure if this is the right section of the forum to post,I think it is)

Let's say there are 50 numbers starting from 1 to 50.They will be grouped like:

1 2 3 4

1 2 3 5

1 2 3 6

...

2 3 4 5

2 3 4 6

2 3 4 7

...

and end with:

47 48 49 50

I want to learn how many "1" number and "2" number(in the same combination) there are in the results.What would be the mathematical formula for calculating this?