diff --git a/src/books.js b/src/books.js
index c8119bb..a233152 100644
--- a/src/books.js
+++ b/src/books.js
@@ -38,29 +38,69 @@
 
 
 // Your code here:
-const booksArray = [];
+const booksArray = [{
+    title: "The Old Man and the Sea",
+    pages: 128,
+    author: "Ernest Hemingway",
+    details: {
+      language: "English",
+      description: "One of Hemingway's most famous works, it tells the story of Santiago..."
+    }
+  }, {
+    title: "The Airbnb Story",
+    pages: 256,
+    author: "Leight Gallagher",
+    details: {
+      language: "English",
+      description: "This is the remarkable behind-the-scenes story of the creation and growth of Airbnb..."
+    }
+  }, {
+    title: "Educated - A Memoir",
+    pages: 352,
+    author: "Tara Westover",
+    details: {
+      language: "English",
+      description: "Educated is an account of the struggle for self-invention..."
+    }
+  }, {
+    title: "The Art of Learning",
+    pages: 288,
+    author: "Josh Waitzkin",
+    details: {
+      language: "English",
+      description: "The Art of Learning takes readers through Waitzkin's unique journey to excellence. He explains in clear detail how a well-thought-out, principled approach to learning is what separates success from failure."
+    }
+  }];
 
 
 
 
 // Iteration 2 | Book Details
-function getBookDetails() {
+function getBookDetails(book) {
   // Your code here:
-
+  return `${book.title} - ${book.author} - ${book.pages} pages`;
 }
 
 
 
 // Iteration 3 | Delete Language
 // Your code here:
-
+function deleteBookLanguage(book) {
+    delete book.details.language;
+    return book;
+}
+booksArray.forEach(deleteBookLanguage);
 
 
 
 // Iteration 4 | Estimated Reading Time
 // Your code here:
-
-
+function estimatedReadingTime(book) {
+    const time = book.pages * 500 / 90;
+    book['readingTime'] = Math.ceil(time);
+    return book;
+}
+booksArray.forEach(estimatedReadingTime);
 
 
 // Bonus: Iteration 5 | Books Dictionary
@@ -86,15 +126,27 @@ const dictionary = {
     ],
 };
 
-function booksByAuthor() {
+function booksByAuthor(dictionary) {
   // Your code here:
-  
+  const result = [];
+  for (const author in dictionary) {
+    const books = dictionary[author];
+    books.forEach(book => {
+      result.push({
+        title: book[0],
+        pages: book[1],
+        author: author
+      });
+    });
+  }
+  return result;
 }
 
 
 
 // Bonus: Iteration 6 | Average Page Count
-function averagePageCount() {
+function averagePageCount(books) {
   // Your code here:
-  
+  const totalPages = books.reduce((sum, book) => sum + book.pages, 0);
+  return totalPages / books.length;
 }