Several elements in response ajax

In my Controller:

fromdp1 - its List<List<string>> , num - its array with numbers , mascoef its array with numbers

var selected = new {fromdp1 ,num, mascoef};
return Json(selected, JsonRequestBehavior.AllowGet);

And my ajax success:

success: function (selected) {
                            $.each(selected, function (a, b) {
                                $.each(b, function (x, y) {
                                    $('<tr>').append(
                                        $('<td>').text(y.Date!!!!(from fromdp1)),
                                        $('<td>').text(selected.num[x]),
                                        $('<td class = "koeff">').text(selected.mascoef[x])
                                    ).appendTo('#res');
                                });
                            });

All arrays of the same size Num[x] and mascoef[x] working , but y.Date not working