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

### Instruction:
David finished his homework in 60 minutes. He spent 15 minutes on his math homework and 18 minutes on his spelling homework. He spent the rest of the time reading for his daily reading log. How many minutes did he spend reading?

### Response:
 เขาใช้เวลาทำการบ้านทั้งหมด 15 + 18 = <<15+18=33>>33 นาที
ดาวิดใช้เวลาอ่าน 60 - 33 = <<60-33=27>>27 นาที