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

### Instruction:
Derrick measures the length of his yard. The length of Alex's yard is half the size of Derrick's and the length of Brianne's yard is 6 times the size of Alex's. If Brianne's yard is 30 yards long, how long is Derrick's yard, in yards?

### Response:
 ความยาวของสวนของเอเล็กซ์คือ 30/6 = <<30/6=5>>5 หลา.
ความยาวของสวนของเดอริคคือ 5 x 2 = <<5*2=10>>10 หลา.