[HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create([Bind(Include = "RequestTestID,PatientID,TestID,DocName,AccountTypeID,TotalPrice,Tests.UnitPrice,AccountTypes.Value,RequestDate")] RequestTest requestTest)
        {
            var model = new RequestTest();
            model.TotalPrice = Convert.ToInt32(requestTest.Tests.UnitPrice * requestTest.AccountTypes.Value);
            if (ModelState.IsValid)
            {

                db.RequestTests.Add(model);
                db.RequestTests.Add(requestTest);
                db.SaveChanges();
                return RedirectToAction("Index");
            }

            ViewBag.AccountTypeID = new SelectList(db.AccountTypes, "AccountTypeID", "AcctTypeName", requestTest.AccountTypeID);
            ViewBag.PatientID = new SelectList(db.Patients, "ID", "LastName", requestTest.PatientID);
            ViewBag.TestID = new SelectList(db.Tests, "TestID", "TestInvestigation", requestTest.TestID);
            return View(requestTest);
        }`
**Model** `  public class Patient
    {
        [Display(Name = "Patient Id")]
        public int ID { get; set; }

        [Required]
        [Display(Name = "Last Name")]
        public string LastName { get; set; }

        [Required]
        [Display(Name = "First Name")]
        public string FirstName { get; set; }

        [Display(Name = "Other Names")]
        public string OtherNames { get; set; }

        [Required]
        [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:dd/MM/yyyy}")]
        [Display(Name = "Date of Birth")]
        public DateTime DoB { get; set; }

        [Required]
        public string Sex { get; set; }

        [Display(Name = "Phone Number")]
        [StringLength(12, MinimumLength = 10)]
        [DataType(DataType.PhoneNumber)]
        public string PhoneNo { get; set; }

        [EmailAddress]
        [Display(Name = "Email Address")]
        public string EmailAddress { get; set; }
        [Display(Name = "Address")]
        public string Address { get; set; }
        public string City { get; set; }
        public virtual ICollection<RequestTest> RequestTestes { get; set; }
        public int HospitalNo { get; set; }

        //[DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:dd/MM/yyyy}")]
        private DateTime? _EnrollmentDate;
        public DateTime? EnrollmentDate { get { return _EnrollmentDate; } set { _EnrollmentDate = DateTime.Now.Date; } }

        ////public virtual JntPatienttest PatientId { get; set; }

    }

    public class RequestTest
    {
        public int RequestTestID { get; set; }
        public int PatientID { get; set; }
        public int TestID { get; set; }
        public string DocName { get; set; }

        public int AccountTypeID { get; set; }


        //private decimal _TotalPrice;

        //public decimal TotalPrice { get { return Add(Tests.UnitPrice, AccountTypes.Value); } set { this._TotalPrice  = value; } }
        public int TotalPrice { get; set; }
        //[DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:dd/MM/yyyy}")]


        [Display(Name = "Request date")]
        private DateTime? _RequestDate;
        public DateTime? RequestDate { get { return _RequestDate; } set { _RequestDate = DateTime.Now.Date; } }
        public virtual Patient Patients { get; set; }
        public virtual Test Tests { get; set; }

        public virtual AccountType AccountTypes { get; set; }

        public static decimal Add(decimal a, decimal b)
        {
            return a * b;
        }

    }
    public class Test
    {
        [DatabaseGenerated(DatabaseGeneratedOption.None)]
        [Display(Name = "Test Id")]
        public int TestID { get; set; }

        [Display(Name = "Test Name")]
        public string TestInvestigation { get; set; }

        public string TestCat { get; set; }

        public decimal UnitPrice { get; set; }

        public string Material { get; set; }

        public string BottleType { get; set; }

        public bool Active { get; set; }

        public int Scode { get; set; }

        public string Status { get; set; }

        public int Bt { get; set; }
        public virtual ICollection<RequestTest> RequestTestes { get; set; }

    }

    public class AccountType
    {
        //[ForeignKey("RequestTestID")]
        [Key]
        public int AccountTypeID { get; set; }

        public string AcctTypeName { get; set; }

        public decimal Value { get; set; }

        //private decimal _Regular;
        //public decimal Regular { get { return _Regular; } set { _Regular = 2; } }
        //public decimal Vip { get; set; }
        //public decimal Nhis { get; set; }
        //public decimal Retenanship { get; set; }
        //public decimal Ihvn { get; set; }
        //public decimal Pedriatics { get; set; }
        //public decimal BloodBank { get; set; }
        //public decimal Emergency { get; set; }
        //public decimal StaffAccount { get; set; }

        public virtual ICollection<RequestTest> RequestTestes { get; set; }

    }` **View**`
@using (Html.BeginForm())
{

    <form method="post" action="~/Views/RequestTests/Create.cshtml">
        @Html.AntiForgeryToken()

        <div class="form-horizontal">
            <h4>RequestTest</h4>
            <hr />
            @Html.ValidationSummary(true, "", new { @class = "text-danger" })
            <div class="form-group">
                @Html.LabelFor(model => model.PatientID, "PatientID", htmlAttributes: new { @class = "control-label col-md-2" })
                <div class="col-md-10">
                    @Html.DropDownList("PatientID", null, htmlAttributes: new { @class = "form-control" })
                    @Html.ValidationMessageFor(model => model.PatientID, "", new { @class = "text-danger" })
                </div>
            </div>

            <div class="form-group">
                @Html.LabelFor(model => model.TestID, "TestID", htmlAttributes: new { @class = "control-label col-md-2" })
                <div class="col-md-10">
                    @Html.DropDownList("TestID", null, htmlAttributes: new { @class = "form-control" })
                    @Html.ValidationMessageFor(model => model.TestID, "", new { @class = "text-danger" })
                </div>
            </div>

            <div class="form-group">
                @Html.LabelFor(model => model.DocName, htmlAttributes: new { @class = "control-label col-md-2" })
                <div class="col-md-10">
                    @Html.EditorFor(model => model.DocName, new { htmlAttributes = new { @class = "form-control" } })
                    @Html.ValidationMessageFor(model => model.DocName, "", new { @class = "text-danger" })
                </div>
            </div>

            <div class="form-group">
                @Html.LabelFor(model => model.AccountTypeID, "AccountTypeID", htmlAttributes: new { @class = "control-label col-md-2" })
                <div class="col-md-10">
                    @Html.DropDownList("AccountTypeID", null, htmlAttributes: new { @class = "form-control" })
                    @Html.ValidationMessageFor(model => model.AccountTypeID, "", new { @class = "text-danger" })
                </div>
            </div>

            @*<div class="form-group">
                @Html.LabelFor(model => model.TotalPrice, htmlAttributes: new { @class = "control-label col-md-2" })
                <div class="col-md-10">
                    @Html.EditorFor(model => model.TotalPrice, new { htmlAttributes = new { @class = "form-control" } })
                    @Html.ValidationMessageFor(model => model.TotalPrice, "", new { @class = "text-danger" })
                </div>
            </div>*@

            <div class="form-group">
                @Html.LabelFor(model => model.RequestDate, htmlAttributes: new { @class = "control-label col-md-2" })
                <div class="col-md-10">
                    @Html.EditorFor(model => model.RequestDate, new { htmlAttributes = new { @class = "form-control" } })
                    @Html.ValidationMessageFor(model => model.RequestDate, "", new { @class = "text-danger" })
                </div>
            </div>

            <div class="form-group">
                <div class="col-md-offset-2 col-md-10">
                    <input type="submit" value="Create" class="btn btn-default" />
                </div>
            </div>
        </div>

    </form>
}`