Ruby - Ayuda con tabulador en Ruby

class Ejercicio

      def initialize ()

      end

      def Desarrollo()

          suma_e = 0

          prom_e = 0

          c_m = 0

          c_f = 0

          puts "ingresar numero de personas:"

          STDOUT.flush  #el STDOUT nos ayudara a limpiar el valor de una variable

          n = gets.chomp

          n = n.to_i

          x = n-1

          a = Array.new

          b = Array.new

          c = Array.new

          for i in 0..x

              print "Persona ",i+1,"\n"

              print "Nombre: "

              a[i] = gets.chomp

              a[i] = a[i].to_s.capitalize

              printf "\n"

              print "Edad: "

              b[i] = gets.chomp

              b[i] = b[i].to_i

              printf "\n"

              print "Genero (M/F) : "

              c[i] = gets.chomp

              c[i] = c[i].to_s.capitalize!

              printf "\n"

          end

          print "-------------------------\n"

          puts "LISTA DE PERSONAS:"

          printf "\n"

          print "Nombre\t\tEdad\tGenero\n"

          print "\n"

          for i in 0..x

                print a[i],"\t", "\t",b[i],"\t",c[i],"\n"

       suma_e = suma_e+b[i]

            end

            for i in 0..x

       if (c[i]=="M")

       c_m=c_m+1

        else

       c_f=c_f+1

        end

            end

            print "-------------------------\n"

            prom_e = suma_e/n

        print "Sumatoria de edades:",suma_e,"\n"

        print "Promedio de edades:",prom_e,"\n"

        print "Cantidad de hombres:",c_m,"\n"

        print "Cantidad de mujeres:",c_f,"\n"

     end

  end

objeto = Ejercicio.new()

objeto.Desarrollo

gets()