jQuery.Ajax调用不起作用

Im passing int data from Js file to controller through Ajax call but data is not being received at the controller end. Here is my Ajax call and Controller Function. Any help will be appritiated

            var cor1 = ((correct / (correct + incorrect)) * 100);
            jQuery.ajax({

                url: '/TakeQuiz/Score',
                type: 'POST',
                contentType: "application/json; charset=utf-8",
                data: {
                    cor: cor1
                },
                dataType: 'json',
                success: function (data) {
                    alert("data:" + data);
                    alert(cor1);
                    $('#completionmessage').html('<h3 class="text-primary">Better luck next time!</h1>');

and my controller function

    [AllowAnonymous]
    [HttpPost]
    public JsonResult Score(int cor = 0)
    {
        var score = Request["t1"];

        return this.Json(cor, JsonRequestBehavior.AllowGet);
    }

right now im doing nothing except receiving value and sending it back. But im receiving the default value i.e 0

Whenever I have this issue it usually helps to create a dto class for the information passed to your viewController

public class JsonResultDto
    {
        public int cor { get; set; }
    }

then in your view controller

    [AllowAnonymous]
    [HttpPost]
    public JsonResult Score(JsonResultDto cor)
    {
        var score = Request["t1"];

        return this.Json(cor, JsonRequestBehavior.AllowGet);
    }