Edit in JSFiddle

var questions = [{
    question: "5x5",
    choices: ["24", "25", "26", "30"],
    correctAnswer: 1
}, {
    question: "6x7",
    choices: ["32", "45", "42", "50"],
    correctAnswer: 2
}, {
    question: "8x9",
    choices: ["70", "72", "71", "75"],
    correctAnswer: 1
}, {
    question: "6x9",
    choices: ["54", "56", "60", "58"],
    correctAnswer: 0
}, {
    question: "4x9",
    choices: ["36", "40", "35", "33"],
    correctAnswer: 0
}];

var currentQuestion = 0;
var correctAnswers = 0;
var quizOver = false;

$(document).ready(function () {
    // Display the first question
    displayCurrentQuestion();
    $(this).find(".quizMessage").hide();
    // On clicking next, display the next question
    $(this).find(".nextButton").on("click", function () {
        if (!quizOver) {

            value = $("input[type='radio']:checked").val();
            if (value == undefined) {
                $(document).find(".quizMessage").text("Please select an answer");
                $(document).find(".quizMessage").show();
            } else {
                // TODO: Remove any message 
                $(document).find(".quizMessage").hide();

                if (value == questions[currentQuestion].correctAnswer) {
                    correctAnswers++;
                }
                currentQuestion++; // Since we have already displayed the first question on DOM ready
                if (currentQuestion < questions.length) {
                    displayCurrentQuestion();
                } else {
                    displayScore();
                    //                    $(document).find(".nextButton").toggle();
                    //                    $(document).find(".playAgainButton").toggle();
                    // Change the text in the next button to ask if user wants to play again
                    $(document).find(".nextButton").text("Play Again?");
                    quizOver = true;
                }
            }
        } else { // quiz is over and clicked the next button (which now displays 'Play Again?'
            quizOver = false;
            $(document).find(".nextButton").text("Next Question");
            resetQuiz();
            displayCurrentQuestion();
            hideScore();
        }
    });

});
// This displays the current question AND the choices
function displayCurrentQuestion() {

    console.log("In display current Question");
    var question = questions[currentQuestion].question;
    var questionClass = $(document).find(".quizContainer > .question");
    var choiceList = $(document).find(".quizContainer > .choiceList");
    var numChoices = questions[currentQuestion].choices.length;

    // Set the questionClass text to the current question
    $(questionClass).text(question);
    // Remove all current <li> elements (if any)
    $(choiceList).find("li").remove();

    var choice;
    for (i = 0; i < numChoices; i++) {
        choice = questions[currentQuestion].choices[i];
        $('<li><input type="radio" value=' + i + ' name="dynradio" />' + choice + '</li>').appendTo(choiceList);
    }
}

function resetQuiz() {
    currentQuestion = 0;
    correctAnswers = 0;
    hideScore();
}
function displayScore() {
    $(document).find(".quizContainer > .result").text("You scored: " + correctAnswers + " out of: " + questions.length);
    $(document).find(".quizContainer > .result").show();
}
function hideScore() {
    $(document).find(".result").hide();
}

<body>
    <div class="quizContainer">
         <h1>Multiplication Quiz</h1>

        <div class="question"> </div> 
        <ul class="choiceList"></ul>
        <div class="quizMessage"></div>
        <div class="result"></div>
        <div class="nextButton">Next Question</div>
        <br>
    </div>
</body>