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

### Instruction:
On Miss Lawrence's math exam, 80% of the 50 questions are problem-solving while the rest are multiple-choice questions. How many multiple-choice questions are there?

### Response:
 80% ของ 50 คำถามเป็นคำถามแก้ปัญหา คำถามปรนัยเหลือ 50 - 40 = <<50-40=10>>10 คำถาม