Why is my return value to "safe" for setting 'check_speed(car_speed)' not working?

def check_speed(car_speed)

  if car_speed >= 40 && car_speed <= 50
    return "safe"
  end

end

instead of puts it needs to be return and that will fix the problem

you are missing a second end.

That may have been part of it, but I wasn't setting the car_speed argument to "safe", which I think is sort of an odd thing to do instead of just outputting safe or not safe and leaving the argument as an integer.

The car speed argument is an integer . Its not a string called 'safe'. What you want to return is the string 'safe'. If you ran the method with a string instead of whats expected, it will give you a comparison error. Your code was correct as you wrote it, it was simply missing a second end. check out www.rep.it and see for yourself. Heres a small program to check the code:

 def check_speed(car_speed)

if car_speed >= 40 && car_speed <=50

puts "safe"

end

end

print 'Enter a check_speed argument' 
speed = gets.chomp
    case speed
      when '40'
      '40'.to_i
      check_speed(40)
      when 'safe'
      check_speed('safe')
      else
         exit
    end