The patch is 16*20=<<16*20=320>>320 square feet

So he needs 320/4=<<320/4=80>>80 patches

The first 10 patches cost 10*10=$<<10*10=100>>100

He gets a discount on the next 80-10=<<80-10=70>>70 patches

They each cost 10/2=$<<10/2=5>>5

So in total they cost 70*5=$<<70*5=350>>350

That means in total he paid 100+350=$<<100+350=450>>450

# Answer

450
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
James wants to build a 16-foot by 20-foot quilt.  He uses patches that are each 4 square feet.  The first 10 patches cost $10 each and then each patch after that cost half as much.  How much do the patches for the quilt cost?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
450
James wants to build a 16-foot by 20-foot quilt.  He uses patches that are each 4 square feet.  The first 10 patches cost $10 each and then each patch after that cost half as much.  How much do the patches for the quilt cost?
train