Lose pounds and inches - How long does it take to lose 40 pounds?

How long does it take to lose 40 pounds?

Im 5'5-5'6. 140 pounds. And 14 about to 15. I have to lose weight for acting. I want to lose it all by November. Is that possible without exercise?

Yeah, if you totally stave yourself, which is a horrible idea, and very unhealthy. The best way is dieting and exercising, you need BOTH.
Firstly, you shouldn't go down to 100 pounds, cuz for your height it is underweight!!
If your dimensions are as you say they are, you would be 100 pounds at 5'5"-5'6". I couldn't recommend that, for any reason whatsoever, especially for acting purposes. I am a retired mental health professional, and have dealt with clients suffering from anorexia nervosa, and I can tell you that being at that weight and height is not healthy. God Bless you.