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

### Instruction:
A sack of rice, which is 50 kilograms,  costs $50. If David sells it for $1.20 per kilogram, how much will be his profit?

### Response:
 รายได้ของเดวิดจากข้าว 50 กิโลกรัมคือ $1.20 x 50 = $<<1.20*50=60>>60
ดังนั้น กำไรของเขาคือ $60 - $50 = $<<60-50=10>>10