Try this:
var data =
    File
        .ReadAllLines(@"@"C:\..\..\..\..\..\..\..\ex1.txt"")
        .Select(line => line.Split(','))
        .Select(parts => new
        {
            city = parts[0],
            temperature = decimal.Parse(parts[1].Trim())
        })
        .ToArray();
Array.ForEach(data, item => Console.WriteLine(item.city));
Console.WriteLine(data.Average(item => item.temperature));
I get this:
Londres
Berlin
New York
Tokyo
11.25
solved c# split and then make math operation [closed]