You want the "choose" function:
a Choose b = a!/[(a-b)!b!]
So, 5 choose 2 = 5!/(3!2!) = 120/(6*2) = 10. So there are 10 ways to choose 2 from a group of 5.
In your case, you want (30c2)*(30c2)*(30c2)*(20c2)*(10c1) = 435*435*435*190*10 = 156 394 462 500 possibilities (156.4 billion)
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