fixes typo in Polymorphic Methods post

tutorials/tour/_posts/2017-02-13-polymorphic-methods.md

@@ -29,6 +29,6 @@ println(listOfDuplicates[Int](3, 4))  // List(3, 3, 3, 3)
 println(listOfDuplicates("La", 8))  // List(La, La, La, La, La, La, La, La)
 ```
 
-The method `listOfDuplicates` takes a type parameter `A` and values parameters `x` and `n`. In this case, value `x` is of type `A`. If `length > 1` we return an empty list. Otherwise we prepend `x` to the the list of duplicates returned by the recursive call to `listOfDuplicates`. (note: `::` means prepend an element on the left to a sequence on the right).
+The method `listOfDuplicates` takes a type parameter `A` and values parameters `x` and `n`. In this case, value `x` is of type `A`. If `length < 1` we return an empty list. Otherwise we prepend `x` to the the list of duplicates returned by the recursive call to `listOfDuplicates`. (note: `::` means prepend an element on the left to a sequence on the right).
 
 When we call `listOfDuplicates` with `[Int]` as the type parameter, the first argument must be an int and the return type will be List[Int]. However, you don't always need to explicitly provide the the type parameter because the compiler can often figure it out based on the type of value argument (`"La"` is a String). In fact, if calling this method from Java it is impossible to provide the type parameter.