After 2 days of pulling my hair I finally nailed it! Anyways, a beginner can always use some feedback. Here's my code:

var quiz = [['How many US states are there?', 50], ['What is the best programming language?', 'JAVASCRIPT'], ['Who painted starry starry night?', 'VINCENT VAN GOGH'] ]; var score = 0;

function print(message) { document.write(message); }

function promptQuiz(questions) {

var correctHTML = '<ol>'; var wrongHTML = '<ol>';

for (i=0; i<questions.length; i++){

var answer = prompt(questions[i][0]); if(answer.toUpperCase() == questions[i][1]){
score ++;
correctHTML += '<li>' + questions[i][0] + ': you answered: ' + answer + '</li>'; } else if(answer.toUpperCase() !== questions[i][1]) { wrongHTML += '<li>' + questions[i][0] + ', answer should be: ' + questions[i][1] + '</li>';
} }

correctHTML += '</ol>'; wrongHTML += '</ol>';

document.write('<h4>Score: ' + score + '</h4>'); document.write('<h3>You answered these questions correctly!'); print(correctHTML);

document.write('<h3>Here are the questions you didn\'t get right:</h3>'); print(wrongHTML);

}

promptQuiz(quiz);