Select 1 unique numbers from 18 to 20
        Total possible combinations (ways)
        
If order does not matter (e.g. most lottery numbers): 3
If order matters (e.g. pick3 numbers, permutations, lock combinations, pin-codes): 3
            
                If order does not matter (e.g. most lottery numbers): 3
If order matters (e.g. pick3 numbers, permutations, lock combinations, pin-codes): 3



