The discount is worth 300*.2=$<<300*.2=60>>60

So the lens cost 300-60=$<<300-60=240>>240

That means he saves 240-220=$<<240-220=20>>20 by buying the cheaper lens

# Answer

20
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Mark has the option of getting a $300 lens with a 20% discount or a $220 lens.  How much money does he save by buying the cheaper lens?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
20
Mark has the option of getting a $300 lens with a 20% discount or a $220 lens.  How much money does he save by buying the cheaper lens?
train