Below is an instruction that describes a task. Write a response that appropriately completes the request in English. Please answer in English.

### Instruction:
John buys dinner plates and silverware.  The silverware cost $20.  The dinner plates cost 50% as much as the silverware.  How much did he pay for everything?

### Response:
The dinner plates cost $20*.5=$<<20*.5=10>>10
So he paid $10 + $20=$<<10+20=30>>30
#### 30