Явный интерфейс

using System;

namespace Shapes
{
    class Person
    {
        string name;
        int age;
        DateTime data { get; set; }
        public Person(string n, DateTime d, int a)
        {
            name = n;
            age = a;
            data = d;
        }
        public override string ToString()
        {
            return String.Format("{0} {1} {2}", data.Date.ToString("d"), name, age);
        }
    }
    interface Iind
    {
        PersonList ReverseList();
        int Count { get; }
        Person this[int i] { get; }
    }
    class PersonList : Iind
    {
        Person[] M;
        int count;
        public PersonList(Person[] l)
        {
            M = l;
            count = l.Length;
        }
ОН РЕАЛИЗУЕТСЯ НАУХЙ
Не слушайте ЕГО
Интерфейс нельзя наследовать
        public Person this[int i]
        {
            get
            {
                return M[i];
            }
        }

        Person Iind.this[int i] => this.M[i];

        int Iind.Count => this.count;


        PersonList Iind.ReverseList()
        {
            Person[] n = new Person[count];
            for (int i = 0; i < count; i++)
                n[i] = M[count - 1 - i];
            return new PersonList(n);
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            Person p1 = new Person("Ivan", new DateTime(2001, 12, 24), 16);
            Person p2 = new Person("Vasya", new DateTime(2000, 8, 23), 12);
            Iind personList = new PersonList(new Person[] { p1, p2 });
            for (int i = 0; i < personList.Count; i++)
                Console.WriteLine(personList[i]);
            for (int i = 0; i < personList.Count; i++)
                Console.WriteLine(personList.ReverseList()[i]);
        }
    }
}