using System;

using System.Linq;

using System.Xml;

using System.Xml.Linq;

​

public static class Program {

    public static void Main(string[] args) {

        string mixed = @"

afajslkfjladsjfl...

<a><b>kjfldkjsf</b>

<c>1024.01</c><d>fajdl;akfjl</d>

</a>

fdsalk;fjl;dakjs: lkdjflak;sjdf;lajd

fajdlkfjlas;djfl;jadsf <e>iopenfkjandsfhae</e> fads;flkadjs;lf

<f>xyeonqrqpeqeqne</f> dfhahen

<g>Monday 8 April 2019</g>adslkfs;fjl;ajdfl;aj

lfjald;fj;aljdflkjafdk,kfkdjf

kfjdkljfk

";

        string xml = "<FOO>" + mixed + "</FOO>";

        XmlDocument doc = new XmlDocument();

        doc.LoadXml(xml);

        var xmlFragments = from XmlNode node1 in doc.FirstChild.ChildNodes 

                           where node1.NodeType == XmlNodeType.Element 

                           select node1;

        foreach (var fragment in xmlFragments) {

            Console.WriteLine(fragment.OuterXml);

        }

​

        XDocument dox = XDocument.Parse(xml);

        var node = dox.Descendants().Where(n => n.Name == "c").FirstOrDefault();

​

        if (node != null)   {

            Console.WriteLine("c:{0}",node.Value);

        }

        else

            Console.WriteLine("none");

        Decimal gst_rate = 1.15M;

        Decimal total_value;

        if(Decimal.TryParse(node.Value, out total_value)){

            var total_excl_gst = Decimal.Round(Decimal.Divide(total_value, gst_rate),2);

            var gst = total_value - total_excl_gst;

            Console.WriteLine("total excluding GST:{0}", total_excl_gst);

            Console.WriteLine("GST:{0}", gst);

        }

    }

​

}