Liz has 11 marbles of different colors. In how many ways can she choose 3 of the marbles, if she refuses to choose the green one and the purple one at the same time?
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Liz has 11 marbles of different colors. In how many ways can she choose 3 of the marbles, if she refuses to choose the green one and the purple one at the same time?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
156
Liz has 11 marbles of different colors. In how many ways can she choose 3 of the marbles, if she refuses to choose the green one and the purple one at the same time?
train