<label><input type="radio" class="catch" name="group1" value="10">10</label>
<label><input type="radio" class="catch" name="group1" value="20">20</label>
<label><input type="radio" class="catch" name="group1" value="30">30</label>
<br>
<label><input type="radio" class="catch" name="group2" value="2">2</label>
<label><input type="radio" class="catch" name="group2" value="3">3</label>
<label><input type="radio" class="catch" name="group2" value="4">4</label>
<br>
<input type="number" class="result" value="" disabled>
<script src="http://yandex.st/jquery/2.1.0/jquery.min.js"></script>
<script>
(function($){
$(document).ready(function(){
$('.catch').on('click change select',function(){
var result = 0;
result += $('.catch[name="group1"]:checked').length > 0 ? parseInt($('.catch[name="group1"]:checked').val()) : 0;
result += $('.catch[name="group2"]:checked').length > 0 ? parseInt($('.catch[name="group2"]:checked').val()) : 0;
$('.result').val(result);
});
});
})(jQuery);
</script>