var numbers = new[] {1,2,3,4};

var minNumber = numbers.Min();
Console.WriteLine(minNumber); //1

var cities = new[] {
    new {Population = 1000},
    new {Population = 2500},
    new {Population = 4000}
};

var minPopulation = cities.Min(c => c.Population);
Console.WriteLine(minPopulation); //1000