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 bags of popcorn for $4 and sells them for $8.  How much profit does he get by selling 30 bags?

### Response:
 แต่ละถุงได้กำไร 8-4=<<8-4=4>>4 เหรียญ
ดังนั้นเขาได้กำไรรวมทั้งหมด 30*4=<<30*4=120>>120 เหรียญ