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

### Instruction:
It takes Derek 9 minutes to walk a mile if he doesn't have to walk with his brother. If he has to take his brother it takes 12 minutes to walk a mile. How many minutes longer would it take him to walk 20 miles if he had to take his brother?

### Response:
 ถ้าเดริคเดินทางคนเดียว เขาจะใช้เวลา 9 x 20 = <<9*20=180>>180 นาที
ถ้าเดริคต้องพาพี่ชายของเขาด้วย เขาจะใช้เวลา 12 x 20 = <<12*20=240>>240 นาที
240 - 180 = <<240-180=60>>60 นาทีมากกว่า