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

### Instruction:
 史蒂夫决定读一本新书。他在周一、周三和周五读了100页。这本书有2100页。需要多少周才能读完？


### Response:
 他每周读3 x 100 = <<3*100=300>>300页
所以需要2100 / 300 = <<2100/300=7>>7周才能读完这本书