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

### Instruction:
 杰夫的手机有16GB的存储空间。他已经使用了4GB。如果一首歌占用大约30MB的存储空间，杰夫的手机可以存储多少首歌？（1GB等于1000MB）


### Response:
 杰夫的手机还剩下12GB的空间
12GB x (1000MB/GB) = 12000MB
12000MB / 30MB = 400首歌