diff --git a/src/question.js b/src/question.js
index 68f6631a..f12e8fa2 100644
--- a/src/question.js
+++ b/src/question.js
@@ -1,7 +1,16 @@
 class Question {
-    // YOUR CODE HERE:
-    //
-    // 1. constructor (text, choices, answer, difficulty)
+    constructor(text, choices, answer, difficulty) {
+        this.text = text;
+        this.choices = choices;
+        this.answer = answer;
+        this.difficulty = difficulty;
+    }
 
-    // 2. shuffleChoices()
-}
\ No newline at end of file
+    shuffleChoices = () => {
+        for (let i = this.choices.length - 1; i > 0; i--) {
+            const j = Math.floor(Math.random() * (i + 1));
+            [this.choices[i], this.choices[j]] = [this.choices[j], this.choices[i]];
+        }
+        return this.choices;
+    };
+}
diff --git a/src/quiz.js b/src/quiz.js
index d94cfd14..c82b4713 100644
--- a/src/quiz.js
+++ b/src/quiz.js
@@ -1,15 +1,55 @@
 class Quiz {
-    // YOUR CODE HERE:
-    //
-    // 1. constructor (questions, timeLimit, timeRemaining)
+    constructor(questions, timeLimit, timeRemaining) {
+        this.questions = questions;
+        this.timeLimit = timeLimit;
+        this.timeRemaining = timeRemaining;
+        this.correctAnswers = 0;
+        this.currentQuestionIndex = 0;
+    }
 
-    // 2. getQuestion()
-    
-    // 3. moveToNextQuestion()
+    getQuestion = () => {
+        console.log(this.questions);
+        return this.questions[this.currentQuestionIndex];
+    };
 
-    // 4. shuffleQuestions()
+    moveToNextQuestion = () => {
+        this.currentQuestionIndex++;
+    };
 
-    // 5. checkAnswer(answer)
+    shuffleQuestions = () => {
+        for (let i = this.questions.length - 1; i > 0; i--) {
+            const j = Math.floor(Math.random() * (i + 1));
+            [this.questions[i], this.questions[j]] = [
+                this.questions[j],
+                this.questions[i],
+            ];
+        }
+        return this.questions;
+    };
 
-    // 6. hasEnded()
+    checkAnswer = (answer) => {
+        let question = this.getQuestion();
+        if (answer === question.answer) {
+            return this.correctAnswers++;
+        }
+    };
+
+    hasEnded = () => {
+        return this.currentQuestionIndex >= this.questions.length;
+    };
+
+    filterQuestionsByDifficulty = (difficulty) => {
+        if (typeof difficulty !== "number" || difficulty < 1 || difficulty > 3) {
+            return this.questions;
+        }
+
+        this.questions = this.questions.filter((question) => question.difficulty === difficulty);
+        return this.questions;
+    };
+
+    averageDifficulty = () => {
+        let difficulties = this.questions.map((question) => question.difficulty)
+        let sumOfDifficulties = difficulties.reduce((accum, currentValue) => accum + currentValue, 0)
+        return sumOfDifficulties / difficulties.length
+    }
 }
\ No newline at end of file