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

### Instruction:
 一列火车在3小时内行驶了270英里。以相同的速度，再行驶180英里需要多少额外的小时？


### Response:
 行驶速度（每小时英里数）= 270英里 / 3小时 = <<270/3=90>>90英里/小时
额外行驶速度（每小时英里数）= 90英里/小时
180英里 / 额外行驶速度 = <<180/(90)=2>>2小时