How to get sum of items between two dates using LINQ in C# .Net

Please refer

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        DataTable dt = new DataTable();
        dt.Columns.AddRange(new DataColumn[3]{ new DataColumn("Item",typeof(int)),
                                                new DataColumn("Date",typeof(DateTime)),
                                                new DataColumn("Id",typeof(int))});
        dt.Rows.Add(70, "8/9/2013", 2);
        dt.Rows.Add(70, "8/10/2013", 3);
        dt.Rows.Add(70, "8/9/2013", 2);
        dt.Rows.Add(42, "8/11/2013", 16);
        dt.Rows.Add(100, "8/12/2013", 16);
        dt.Rows.Add(16, "8/13/2013", 16);
        dt.Rows.Add(36, "8/15/2013", 4);
        dt.Rows.Add(90, "8/16/2013", 2);
        //You need to change your line like this
        var sum1 = dt.AsEnumerable().Where(dr => dr.Field<int>("Id") == 16 && (dr.Field<DateTime>("Date").Date >= Convert.ToDateTime("08/11/2013") && dr.Field<DateTime>("Date").Date <= Convert.ToDateTime("08/15/2013"))).Select(dr => dr.Field<int>("Item")).Sum();
    }
}

Thank You.