obtain three times repeated values in arraylist.. how..

Question

Hello my friends...

I have an arraylist les say  

string[] list = new list{4,5,6,6,7,8,6,7,3,8,7,9,7 };

I want to identify the three times repeated values  in arraylist list.

e.g. program will output that:

The value 6 is repeated three times..

The value 7 is repeated 4 times..

note: I don't need the whole program.. I just don't have any idea how a value is checked whether if it  repeated itself three or more times....

help please....