Random String array return

I tried to create a code that outputs a random question. However, constantly I get the error 'Incompatible types: Int cannot be converted to Question'. Ofcourse I tried to find the reason online in various topics, but I could not get the answer to this error in my case. I am new to this, so it might be I just couldn't translate the given answers to my own example. The error is in the lines:

        questions[i]=temp;
        temp = questions[index];

This snippet can be found in the following code:

    public static void main(String[] args){
    Scanner keyboardInput = new Scanner(System.in);

    System.out.println("Welcome to the geography quiz");
    System.out.println("Press a key to begin");            
    String start = keyboardInput.nextLine();

    String q1 = "What is the capital of Belgium?";
    String q2 = "\nWhat is the capital of Chile?";
    String q3 = "\nWhat is the capital of the Netherlands?";

    Question[]questions={
        new Question(q1, "Brussels", "No alternative"),
        new Question(q2, "Santiago de Chile", "Santiago"),
        new Question(q3, "Amsterdam", "No alternative")
    };

    takeTest(questions);
}

public static void takeTest(Question[]questions){
    int score = 0;
    int index, temp;
    Scanner keyboardInput = new Scanner(System.in);

    Random rnd = new Random();
    for(int i= questions.length -1; i>0; i--){
        index = rnd.nextInt(i+1);
        questions[index] = questions[i];
        questions[i]=temp;
        temp = questions[index];

        System.out.println(questions[i].prompt);
        String a = keyboardInput.nextLine();          

        if (a.equalsIgnoreCase(questions[i].answer)) {
            score++;
        }else if(a.equalsIgnoreCase(questions[i].alternative)){
            score++;
        }
    } 
    System.out.println("You got " + score + " out of " + questions.length);
}

Thanks for your help!