Check my code out and comment please. This was how I worked it out, totally different and maybe more difficult approach

var questions = [ ['How many states are in the United States?', 50],
                  ['How many continents are there?', 7],
                  ['How many legs does an insect have?', 6]
                ];
var right = 0;
var correct = '<ol>';
var wrong = '<ol>';

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

for( i = 0; i < questions.length; i += 1 ) {
  answers = prompt(questions[i][0]);
  if ( parseInt(answers) === questions[i][1] ) {
    right += 1;
    correct += '<li>' + questions[i][0] + '</li>';  
  } if ( parseInt(answers) !== questions[i][1] )
  {
    wrong += '<li>' + questions[i][0] + '</li>';
  }
}

if ( right === 0 || right === 2 ) {
  print('You got ' + right + ' question(s) right.');
} else {
  print('You got ' + right + ' question right.');
}


print('<h2>' + 'You got these questions correct:' + '</h2>');
print(correct);

print('<h2>' + 'You got these questions wrong:' + '</h2>');
print(wrong);