see, https://gist.github.com/FromAtom/6511976

arrenger.rb

class Arranger
  def initialize(capacity, file_path)
    @capacity = capacity

    @members = parse_members_text(file_path)
    @members.shuffle!
  end

  def decision
    @members.first(@capacity)
  end

  def next_decision
    @members.last(@members.length - @capacity)
  end

  private
  def parse_members_text(file_path)
    text = File.read(file_path, encoding: Encoding::UTF_8)
    text.rstrip.split(/\r?\n/).map { |line| line.chomp }
  end
end

snorkel_driver = Arranger.new(6, "snorkel_members.txt")
puts "---First car members---"
puts snorkel_driver.decision
puts "---Second car members---"
puts snorkel_driver.next_decision

glassboat_driver = Arranger.new(6, "glassboat_members.txt")
puts "---First car members---"
puts glassboat_driver.decision
puts "---Second car members---"
puts glassboat_driver.next_decision