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

### Instruction:
Archie is playing with his marbles outside. He loses 60% of them into the street. Of the remaining ones, he loses half down a sewer. If he has 20 left, how many did he start with?

### Response:
 เขามี 40 ลูกแก้วก่อนที่จะสูญเสียลงท่อระบายน้ำ เพราะ 20 x 2 = <<40=40>>40
เขาเริ่มต้นมี 100 ลูกแก้ว เพราะ 40/.4 = 100