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

### Instruction:
Ryan builds model mustang cars.  A full size mustang is 240 inches long.  The mid-size model that Ryan creates is 1/10th the size, and the smallest model that Ryan creates is half the size of the mid-size model.  How many inches long is the smallest model mustang?

### Response:
 รุ่นกลาง: 240/10 = <<240/10=24>>24 นิ้ว
รุ่นเล็กที่สุด: 24/2 = <<24/2=12>>12 นิ้ว