Fixed spelling mistakes and edit the problem statement sentence and solution sentence to reflect codes intention

Author: aididjaafar

chapters/arrays/define-ranges.md

@@ -5,11 +5,11 @@ chapter: Arrays
 ---
 ## Problem
 
-You want to define range in array.
+You want to define a range in an array.
 
 ## Solution
 
-There are two method to define range of an array element in CoffeeScript.
+There are two ways to define a range of array elements in CoffeeScript.
 
 {% highlight coffeescript %}