ExamResultV2

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ExamResultV2
{
    class ExamResultV2
    {
        static void Main()
        {
            Dictionary<string, List<double>> resultFromExam = new Dictionary<string, List<double>>();
            resultFromExam["Jackson"] = new List<double>() { 5.2555, 3.25, 5.50 };
            resultFromExam["Krstina"] = new List<double>() { 7.5, 6.7, 8,0 };
         foreach(var r in resultFromExam)
            {
                var personName = r.Key;
                List<string> result = new List<string>();
                var marks = r.Value;
                foreach(var mark in marks)
                {

                    result.Add(string.Format("{0:F2}", mark));
                }
                var marksForPrint = string.Join(", ", result);
                Console.WriteLine("{0} - - {1}",personName,marksForPrint);
            }
        }
    }
}