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

### Instruction:
Grayson has 100 questions on a test. He answers some of the questions for 2 hours, taking two minutes for each answer, then realizes he doesn't know the rest of the questions. How many questions does Grayson leave unanswered when he submits his test?

### Response:
 2 ชั่วโมงเท่ากับ 60 * 2 = <<60*2=120>>120 นาที
ถ้าแต่ละข้อใช้เวลา 2 นาที เกรย์สันตอบได้ 120 / 2 = <<120/2=60>>60 ข้อ
ข้อที่ไม่ได้ตอบคือ 100 - 60 = <<100-60=40>>40 ข้อ