var numQuestions;

function hideAnswers() {
   for (i = 0; i < numQuestions; i++) {
      document.getElementById('a' + i).style.display = 'none'; }
}

function toggleAnswer(answer) {
   var item;

   item = document.getElementById(answer).style;
   if (item.display == 'none') {
      item.display = 'block'; }
   else item.display = 'none';
}