diff --git a/src/movies.ts b/src/movies.ts
index 3dd9e0c..dd6c3e2 100644
--- a/src/movies.ts
+++ b/src/movies.ts
@@ -53,9 +53,7 @@ const movies: Movie[] = [
  *  hasKey({ title: "Inception", year: 2010 }, "director"); // => false
  */
 function hasKey(obj: object, key: string): boolean {
-  // write your code here...
-
-  return true; // replace true with what you see is fit
+  return Object.keys(obj).includes(key);
 }
 
 /**
@@ -64,7 +62,9 @@ function hasKey(obj: object, key: string): boolean {
  * - Logs each movie title provided in the array of movies.
  */
 function printMovieTitles(movies: Movie[]): void {
-  // write your code here...
+  movies.forEach((movie) => {
+    console.log(movie.title);
+  });
 }
 
 /**
@@ -81,7 +81,7 @@ function printMovieTitles(movies: Movie[]): void {
 function countMoviesByYear(movies: Movie[], year: number): number {
   // write your code here...
 
-  return -1; // replace -1 with what you see is fit
+  return movies.filter((movie) => movie.year === year).length;
 }
 
 /**
@@ -108,9 +108,13 @@ function updateMovieGenre(
   title: string,
   newGenre: string
 ): Movie[] {
-  // write your code here...
+  const movieToUpdate = movies.find((movie) => movie.title === title);
+
+  if (movieToUpdate) {
+    movieToUpdate.genre = newGenre;
+  }
 
-  return []; // replace empty array with what you see is fit
+  return movies;
 }
 
 export { Movie, hasKey, printMovieTitles, countMoviesByYear, updateMovieGenre };