Why can't my mom stop smoking?

She smokes and smokes and smokes. All day every day as soon as she has stumped one out she has lit one up again. All her money goes on these things... it is terrible. I have given her a challenge where she tries and stops for an hour but she never succeeds. She just gets all grumpy at me and moody. She borrows money off me all the time and I am sick of it... how do I get her to cut down or stop? She smokes about 100 to 150 a day by the way.