How to set up probability of numeric recurrence in lottery

[ArfDogXYZ]

Hi,
It has been a long time, and I do not remember how to set up a probability calculation with the following variables -
take a lottery that draws 12 numbers, values 0-9 only, from a hopper that replaces the number after it is drawn, i.e. probability of each number appearing remains constant.
How do I set up an equation to determine probability of, say
2 numbers each appearing 3 times
1 number 3 times and 1 number 4 times, etc... (can be any two numbers, just want to calculate probability of it happening at all, not for specific digits.)
any help appreciated, thanks

 

[robert Ihnot]

This is an easy problem. Take dice, what chance is there to get "snake eyes"? Well the 2 can occur in only one way (which is the case with the numbers you are mentioning) and so of the 36 possibilities with two dice there is only 1/36 chance that it will come on the next roll. To come up twice would be: 1/36 x 1/36 = 1/1296, but it will happen anyway!