diff --git a/index.js b/index.js
index 2bb3c16..504c8e7 100644
--- a/index.js
+++ b/index.js
@@ -1,19 +1,22 @@
-/*
-Native Array Methods pt.2 continues with the same dataset: songs. All required functions and array methods (forEach, map, find, some/every, sort) are combined into a single file, each addressing a distinct problem.
-*/
-
+/**********************************************************************************/
+/* Native Array Methods pt.2 continues with the same dataset: songs.              */
+/* All required functions and array methods (forEach, map, find, some/every, sort) */
+/* are combined into a single file, each addressing a distinct problem.            */
+/**********************************************************************************/
 
+const songs = require("./data/songs");
 const exampleSongData = require("./data/songs");
 // Do not change the line above.
 
-
 // #1
 /**
  * Returns the titles of songs sorted alphabetically.
  * @param {Object[]} songs - An array of songs.
  * @returns {string[]} Sorted song titles.
  */
-function getSortedTitles(songs) {}
+function getSortedTitles(songs) {
+  return songs.map((song) => song.title).sort();
+}
 
 // #2
 /**
@@ -22,15 +25,30 @@ function getSortedTitles(songs) {}
  * @param {string} albumName - Name of the album.
  * @returns {string[]} An array of song titles.
  */
-function getSongsFromAlbum(songs, albumName) {}
+function getSongsFromAlbum(songs, albumName) {
+  return songs
+    .filter((song) => song.album == albumName)
+    .map((song) => song.title);
+}
 
-// #3 
+// #3
 /**
  * Categorizes and counts songs based on their runtime.
  * @param {Object[]} songs - An array of songs.
  * @returns {Object} An object with counts of short, medium, and long songs.
  */
-function categorizeSongsByRuntime(songs) {}
+function categorizeSongsByRuntime(songs) {
+  const short = songs.filter((song) => song.runtimeInSeconds < 180);
+  const medium = songs.filter(
+    (song) => song.runtimeInSeconds >= 180 && song.runtimeInSeconds < 300
+  );
+  const long = songs.filter((song) => song.runtimeInSeconds >= 300);
+  return {
+    shortSongs: short.length,
+    mediumSongs: medium.length,
+    longSongs: long.length,
+  };
+}
 
 // #4
 /**
@@ -38,7 +56,23 @@ function categorizeSongsByRuntime(songs) {}
  * @param {Object[]} songs - An array of songs.
  * @returns {string} The name of the album with the most songs.
  */
-function findAlbumWithMostSongs(songs) {}
+function findAlbumWithMostSongs(songs) {
+  const outputAlbum = {
+    name: "",
+    numSongs: 0,
+  };
+  let albuns = songs.map((song) => song.album);
+  albuns
+    .filter((album, idx) => albuns.indexOf(album) === idx)
+    .forEach((album) => {
+      const numSongs = songs.filter((song) => song.album == album).length;
+      if (outputAlbum.numSongs <= numSongs) {
+        outputAlbum.name = album;
+        outputAlbum.numSongs = numSongs;
+      }
+    });
+  return outputAlbum.name;
+}
 
 // #5
 /**
@@ -47,7 +81,9 @@ function findAlbumWithMostSongs(songs) {}
  * @param {string} albumName - Name of the album.
  * @returns {Object|null} First song object in the album or null.
  */
-function getFirstSongInAlbum(songs, albumName) {}
+function getFirstSongInAlbum(songs, albumName) {
+  return songs.filter((song) => song.album == albumName)[0];
+}
 
 // #6
 /**
@@ -56,7 +92,9 @@ function getFirstSongInAlbum(songs, albumName) {}
  * @param {number} runtime - The runtime to check against in seconds.
  * @returns {boolean} True if there is at least one song longer than the runtime.
  */
-function isThereLongSong(songs, runtime) {}
+function isThereLongSong(songs, runtime) {
+  return songs.some((song) => song.runtimeInSeconds > runtime);
+}
 
 // #7
 /**
@@ -64,7 +102,12 @@ function isThereLongSong(songs, runtime) {}
  * @param {Object[]} songs - An array of songs.
  * @returns {Object[]} Array of song objects with runtime in minutes.
  */
-function getSongsWithDurationInMinutes(songs) {}
+function getSongsWithDurationInMinutes(songs) {
+  return songs.map((song) => {
+    song.durationInMinutes = song.runtimeInSeconds / 60;
+    return song;
+  });
+}
 
 // #8
 /**
@@ -72,7 +115,21 @@ function getSongsWithDurationInMinutes(songs) {}
  * @param {Object[]} songs - An array of songs.
  * @returns {string[]} Array of album names in reverse alphabetical order.
  */
-function getAlbumsInReverseOrder(songs) {}
+function getAlbumsInReverseOrder(songs) {
+  const albuns = [];
+  songs.forEach((song) => {
+    if (!albuns.includes(song.album)) {
+      albuns.push(song.album);
+    }
+  });
+  return albuns.sort((a, b) => {
+    if (a < b) {
+      return 1;
+    } else {
+      return -1;
+    }
+  });
+}
 
 // #9
 /**
@@ -81,7 +138,15 @@ function getAlbumsInReverseOrder(songs) {}
  * @param {string} word - The word to search for in song titles.
  * @returns {string[]} An array of song titles containing the word.
  */
-function songsWithWord(songs, word) {}
+function songsWithWord(songs, word) {
+  return songs
+    .map((song) => song.title)
+    .filter((song) => {
+      if (song.includes(word)) {
+        return song;
+      }
+    });
+}
 
 // #10
 /**
@@ -90,21 +155,43 @@ function songsWithWord(songs, word) {}
  * @param {string} artistName - Name of the artist.
  * @returns {number} Total runtime in seconds.
  */
-function getTotalRuntimeOfArtist(songs, artistName) {}
+function getTotalRuntimeOfArtist(songs, artistName) {
+  return songs
+    .filter((song) => song.artist == artistName)
+    .reduce((totalRuntime, song) => (totalRuntime += song.runtimeInSeconds), 0);
+}
 
 // Problem #11
 /**
  * Prints artists who have more than one song in the list.
  * @param {Object[]} songs - An array of songs.
  */
-function printArtistsWithMultipleSongs(songs) {}
+function printArtistsWithMultipleSongs(songs) {
+  let artists = songs.map((song) => song.artist);
+  artists
+    .filter((artist, idx) => artists.indexOf(artist) === idx)
+    .forEach((artist) => {
+      const artistSongs = songs.filter((song) => song.artist == artist);
+      if (artistSongs.length > 1) {
+        console.log(artist);
+      }
+    });
+}
 
 // Problem #12
 /**
  * Logs the longest song title.
  * @param {Object[]} songs - An array of songs.
  */
-function printLongestSongTitle(songs) {}
+function printLongestSongTitle(songs) {
+  let longestSongTitle = "";
+  songs.forEach((song) => {
+    if (song.title.length > longestSongTitle.length) {
+      longestSongTitle = song.title;
+    }
+  });
+  console.log(longestSongTitle);
+}
 
 // Problem #13
 /**
@@ -112,7 +199,13 @@ function printLongestSongTitle(songs) {}
  * @param {Object[]} songs - An array of songs.
  * @returns {Object[]} Sorted array of songs.
  */
-function sortSongsByArtistAndTitle(songs) {}
+function sortSongsByArtistAndTitle(songs) {
+  return songs.sort((songA, songB) => {
+    const artistCompare = songA.artist.localeCompare(songB.artist);
+    const titleCompare = songA.title.localeCompare(songB.title);
+    return artistCompare || titleCompare;
+  });
+}
 
 // Problem #14
 /**
@@ -120,7 +213,17 @@ function sortSongsByArtistAndTitle(songs) {}
  * @param {Object[]} songs - An array of songs.
  * @returns {Object} An object mapping each album to its total runtime.
  */
-function listAlbumTotalRuntimes(songs) {}
+function listAlbumTotalRuntimes(songs) {
+  const albumTotalRuntimes = {};
+  songs.forEach((song) => {
+    if (albumTotalRuntimes.hasOwnProperty(song.album)) {
+      albumTotalRuntimes[song.album] += song.runtimeInSeconds;
+    } else {
+      albumTotalRuntimes[song.album] = song.runtimeInSeconds;
+    }
+  });
+  return albumTotalRuntimes;
+}
 
 // Problem #15
 /**
@@ -129,7 +232,9 @@ function listAlbumTotalRuntimes(songs) {}
  * @param {string} letter - The letter to search for.
  * @returns {Object|null} The first song object that matches the criterion or null.
  */
-function findFirstSongStartingWith(songs, letter) {}
+function findFirstSongStartingWith(songs, letter) {
+  return songs.find((song) => song.title[0] == letter.toUpperCase());
+}
 
 // Problem #16
 /**
@@ -137,7 +242,17 @@ function findFirstSongStartingWith(songs, letter) {}
  * @param {Object[]} songs - An array of songs.
  * @returns {Object} An object mapping each artist to an array of their song titles.
  */
-function mapArtistsToSongs(songs) {}
+function mapArtistsToSongs(songs) {
+  const artistSongs = {};
+  songs.forEach((song) => {
+    if (artistSongs.hasOwnProperty(song.artist)) {
+      artistSongs[song.artist].push(song.title);
+    } else {
+      artistSongs[song.artist] = [song.title];
+    }
+  });
+  return artistSongs;
+}
 
 // Problem #17
 /**
@@ -145,21 +260,67 @@ function mapArtistsToSongs(songs) {}
  * @param {Object[]} songs - An array of songs.
  * @returns {string} The name of the album with the longest average song runtime.
  */
-function findAlbumWithLongestAverageRuntime(songs) {}
+function findAlbumWithLongestAverageRuntime(songs) {
+  const outputAlbum = {
+    name: "",
+    avgRuntime: 0,
+  };
+  let albuns = songs.map((song) => song.album);
+  albuns
+    .filter((album, idx) => albuns.indexOf(album) === idx)
+    .forEach((albun) => {
+      const albumSongs = songs.filter((song) => song.album == albun);
+      const totalRuntime = albumSongs.reduce(
+        (acc, song) => acc + song.runtimeInSeconds,
+        0
+      );
+      const avgRuntime = totalRuntime / albumSongs.length;
+      if (outputAlbum.avgRuntime <= avgRuntime) {
+        outputAlbum.name = albun;
+        outputAlbum.avgRuntime = avgRuntime;
+      }
+    });
+  return outputAlbum.name;
+}
 
 // Problem #18
 /**
  * Logs song titles sorted by their runtime.
  * @param {Object[]} songs - An array of songs.
  */
-function printSongsSortedByRuntime(songs) {}
+function printSongsSortedByRuntime(songs) {
+  return songs
+    .sort((songA, songB) => {
+      if (songA.runtimeInSeconds <= songB.runtimeInSeconds) {
+        return -1;
+      } else {
+        return 1;
+      }
+    })
+    .forEach((song) => console.log(song.title));
+}
 
 // Problem #19
 /**
  * Prints a summary of each album, including its name, total runtime, and number of songs.
  * @param {Object[]} songs - An array of songs.
  */
-function printAlbumSummaries(songs) {}
+function printAlbumSummaries(songs) {
+  let albuns = songs.map((song) => song.album);
+  albuns = albuns
+    .filter((album, idx) => albuns.indexOf(album) === idx)
+    .forEach((album) => {
+      const albumSongs = songs.filter((song) => song.album == album);
+      const numSongs = albumSongs.length;
+      const totalRuntime = albumSongs.reduce(
+        (acc, song) => acc + song.runtimeInSeconds,
+        0
+      );
+      console.log(
+        `${album}: ${numSongs} songs, Total Runtime: ${totalRuntime} seconds`
+      );
+    });
+}
 
 // Problem #20
 /**
@@ -167,13 +328,30 @@ function printAlbumSummaries(songs) {}
  * @param {Object[]} songs - An array of songs.
  * @returns {string} The name of the artist with the most songs.
  */
-function findArtistWithMostSongs(songs) {}
 
+function findArtistWithMostSongs(songs) {
+  const outputArtist = {
+    name: "",
+    numSongs: "",
+  };
+  const artists = songs.map((song) => song.artist);
+  artists
+    .filter((artist, idx) => artists.indexOf(artist) === idx)
+    .forEach((artist) => {
+      const numSongs = songs.filter((song) => song.artist == artist).length;
+
+      if (outputArtist.numSongs < numSongs) {
+        outputArtist.name = artist;
+        outputArtist.numSongs = numSongs;
+      }
+    });
+  return outputArtist.name;
+}
 
 module.exports = {
   getSortedTitles,
   getSongsFromAlbum,
-  categorizeSongsByRuntime, 
+  categorizeSongsByRuntime,
   findAlbumWithMostSongs,
   getFirstSongInAlbum,
   isThereLongSong,
@@ -190,5 +368,5 @@ module.exports = {
   findAlbumWithLongestAverageRuntime,
   printSongsSortedByRuntime,
   printAlbumSummaries,
-  findArtistWithMostSongs
-};;
+  findArtistWithMostSongs,
+};