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

### Instruction:
John buys cans of soup for buy 1 get one free.  He gets 30 cans with a normal price of $0.60.  How much does he pay?

### Response:
 เขาจ่ายเงินสำหรับกระป๋องซุป 30/2=<<30/2=15>>15 กระป๋อง
ซึ่งมีราคา 15*.6=$<<15*.6=9>>9