Reduce, Min, MinBy, Sum and MkString

  case class Person(name : String, age : Int)

  val team = List(Person("Moni", 29), Person("Anna", 30), Person("Hannes", 40));
  val ages = team.map(_.age);
  val names = team.map(_.name);
  
  println(ages.reduce(Math.min(_,_)));
  println(ages.min);
  println(team.minBy(_.age));
  
  println(ages.reduce(_+_) / ages.size);
  println(ages.sum / ages.size);
  
  println(names.reduce(_+", "+_));
  println(names.mkString(", "));