Select 21 unique numbers from 0 to 20
        Total possible combinations (ways)
        
If order does not matter (e.g. most lottery numbers): 1
If order matters (e.g. pick3 numbers, permutations, lock combinations, pin-codes): 51,090,942,171,709,440,000 (~51 quintillion)
            
                If order does not matter (e.g. most lottery numbers): 1
If order matters (e.g. pick3 numbers, permutations, lock combinations, pin-codes): 51,090,942,171,709,440,000 (~51 quintillion)



