Stackoverflow - Converting Sql Query to LinQ with Reverse SQL Command, C#

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//Rextester.Program.Main is the entry point for your code. Don't change it.
//Compiler version 4.0.30319.17929 for Microsoft (R) .NET Framework 4.5

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;

namespace Rextester
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var people = new List<Person>()
            {
                new Person() {FirstName = "Zohar", LastName = "Peled"},
                new Person() {FirstName = "Spidy", LastName = "787"},
                new Person() {FirstName = "Darren", LastName = "Sherwood"},
                    new Person() {FirstName = "R. Martinho", LastName = "Fernandes"},
                    new Person() {FirstName = "RobinHood70"}
            };

var query = from person in people
                        select person.FirstName.Reverse().Capitalize();

foreach (var res in query)
            {
                Console.WriteLine(res);
            }
        }
    }
    
    public class Person
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }
    }

public static class StringExtensions
    {

public static string Reverse(this string s)
        {
            if(string.IsNullOrEmpty(s))
            {
                return s;
            }
            var info = new StringInfo(s);
            var sb = new StringBuilder();

for(int i = info.LengthInTextElements - 1; i > -1 ; i--)
            {
                sb.Append(info.SubstringByTextElements(i, 1));
            }
            return sb.ToString();
        }

public static string Capitalize(this string s)
        {
            if(string.IsNullOrEmpty(s))
            {
                return s;
            }
            var charArray = s.ToLower().ToCharArray();
            charArray[0] = Char.ToUpper(charArray[0]);
            return new string(charArray);
        }
    }
}

Show compiler warnings [ + ] Show input
Compilation time: 0,16 sec, absolute running time: 0,09 sec, cpu time: 0,09 sec, average memory usage: 13 Mb, average nr of threads: 3