C#

using System;
using System.Linq;
using System.Xml.Linq;

class Program
{
    static void Main()
    {
        XDocument document = XDocument.Load(@"d:\test.xml");

        var priceInfo = from e in document.Descendants("MPrice").Elements("Price")
                        let start = DateTime.Parse(e.Descendants("StartDt").FirstOrDefault().Value)
                        let end = DateTime.Parse(e.Descendants("EndDt").FirstOrDefault().Value)
                        where start < DateTime.Now && end > DateTime.Now
                        select new { Id = e.Parent.Element("Id").Value, ListPrice = e.Element("ListPrice").Value };

        Console.WriteLine(priceInfo.FirstOrDefault().Id);
        Console.WriteLine(priceInfo.FirstOrDefault().ListPrice);
    }
}

The following is the metatag:
<ns2:RetsubPack serviceSuccessful="true" returnCode="0" xmlns:ns2="http://test1/test">
    <statusDescription>Package Details retrieved Successfully</statusDescription>
    <PackageDetails>
        <Type>type2</Type>
        <Category>dog</Category>
        <ContName>Co 1</ContgName>
        <TotalTrans>0</TotalTrans>
     </PackageDetails>
    <NumberOfDocuments>3</NumberOfDocuments>
    <subDocuments attachmentId="xx1">
        <DocumentMetadata>
            <DocumentTypeCode>Spreadsheet1</DocumentTypeCode>
            <PackageId>pkg1</PackageId>
        </DocumentMetadata>
    </subDocuments>
    <subDocuments attachmentId="xx2">
        <DocumentMetadata>
            <DocumentTypeCode>Spreadsheet2</DocumentTypeCode>
            <PackageId>pkg1</PackageId>
        </DocumentMetadata>
    </subDocuments>
    <subDocuments attachmentId="xx3">
       
</ns2:RetsubPack>

A) It must contain at least one vowel. 
B) It cannot contain three consecutive vowels or three consecutive consonants. 
C) It cannot contain two consecutive occurrences of the same letter, except for 'ee' or 'oo'. 

<?xml version="1.0" encoding="utf-8"?>
<Contacts>
  <Contact>
    <ContactId>0</ContactId>
    <Prefix>
    </Prefix>
    <FirstName>Kevin</FirstName>
    <MiddleName>Marois</MiddleName>
    <LastName>Brian</LastName>
    <Suffix>
    </Suffix>
    <Birthday>1965-10-11</Birthday>
    <Title>Senior Software Engineer</Title>
    <Comments>has 25 years of development experience</Comments>
  </Contact>
  <Contact>
    <ContactId>1</ContactId>
    <Prefix>Dr.</Prefix>
    <FirstName>Henry</FirstName>
    <MiddleName>DeCarlo</MiddleName>
    <LastName>G</LastName>
    <Suffix>III</Suffix>
    <Birthday>1965-10-11</Birthday>
    <Title>Oral Surgeon</Title>
    <Comments>His office is over on 23rd street</Comments>
  </Contact>
  <Contact>
    <ContactId>2</ContactId>
    <Prefix>
    </Prefix>
    <FirstName>Mattew</FirstName>
    <MiddleName>Damon</MiddleName>
    <LastName>Paige </LastName>
    <Suffix>
    </Suffix>
    <Birthday>1970-10-08</Birthday>
    <Title>Actor</Title>
    <Comments>Excellent actor</Comments>
  </Contact>
</Contacts>

public void DeleteContact(int ContactId)
{
    XmlDocument doc = new XmlDocument();
    doc.Load(XMLFile);
    var path = "/contacts/contact[@ContactId='" + ContactId + "']";
    XmlNode t = doc.SelectSingleNode(path);
    t.ParentNode.RemoveChild(t);
    doc.Save(XMLFile);
}