update functions' exercises

docs/python/python_fundamentals_1/functions.ipynb

@@ -1183,8 +1183,7 @@
     "\n",
     "1. Write a function called is_prime, which checks if a number is prime.\n",
     "1. Write a functions which checks if all items are unique in the list.\n",
-    "1. Write a function which checks if all the items of the list are of the same data type.\n",
-    "1. Write a function which check if provided variable is a valid python variable"
+    "1. Write a function which checks if all the items of the list are of the same data type."
    ]
   }
  ],