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

### Instruction:
Maiya has two sisters. The first sister is twice as old as Maiya. The first sister is 1 year younger than Maiya. Their average age is 5. How old is Maiya?

### Response:
 อายุรวมของพวกเขาคือ 15 เพราะ 3 x 5 = <<3*5=15>>15
15 - X - 2X -(X-1) เท่ากับ 16=15
X=16/4
X = 4 ปี