Each shirt cost 20*.5=$<<20*.5=10>>10 with the sale

So he paid 10*6=$<<10*6=60>>60

# Answer

60
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
James buys 6 t-shirts for 50% off.  They each cost $20.  How much did he pay?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
60
James buys 6 t-shirts for 50% off.  They each cost $20.  How much did he pay?
train