<ol type="a">
  <li><input type="radio" name="answer0[]">A</li>
  <li><input type="radio" name="answer0[]">A</li>
  <li><input type="radio" name="answer0[]">A</li>
</ol>
<ol type="a">
  <li><input type="checkbox" name="answer1[]">A</li>
  <li><input type="checkbox" name="answer1[]">A</li>
  <li><input type="checkbox" name="answer1[]">A</li>
</ol>

$('ol').each(function (i) {
    $(this).find("input:first").prop("required", true);
});

$('ol').each(function (i) {
    $("[name='answer"+i+"[]']").rules("add", {required:true});
});

var rules = {};

$('ol [type="checkbox"], ol [type="radio"]').each(function(i,el){
    var name = $(el).attr('name');
    if(rules[name] === undefined){
        rules[name] = {
            required: true
        };
    }
});

$("#myform").validate({
    rules: rules
});

$('ol').each(function (i) {
    $(this).find("input[type='checkbox']").prop("required", true);
});

$('ol').find('input[type="checkbox"]:checked').length