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

### Instruction:
Joe goes camping with his dad on a Friday. Joe's dad has 21 marshmallows, and Joe has four times as much marshmallows as his dad. If Joe’s dad roasts a third of his marshmallows, and Joe roasts half of his marshmallows, how many marshmallows did they roast in total?

### Response:
 พ่อของโจย่างมาร์ชแมลโลว์ไป 21/3 = <<21/3=7>>7 ลูก
โจมีมาร์ชแมลโลว์ 21*4 = <<21*4=84>>84 ลูก
โจย่างมาร์ชแมลโลว์ไป 84/2 = <<84/2=42>>42 ลูก
โจและพ่อของโจย่างมาร์ชแมลโลว์ทั้งหมด 7+42 = <<7+42=49>>49 ลูก